深海游弋的鱼 – 默默的点滴

Thymeleaf调用Spring的Bean的函数

问题见：https://stackoverflow.com/questions/53803497

为什么按照官网上的写法调用@Bean报错：EL1057E: No bean resolver registered in the context to resolve access to bean

有时候我们希望自己去通过thymeleaf进行解析文本，调用自定义的函数。比如

Context context = new Context();
context.setVariables(dataMap);
templateEngine.process(templateName, context);

Context context = new Context();

context.setVariables(dataMap);

templateEngine.process(templateName, context);

如果我们在模板里使用了 ${@beanName.method()}，此时会报错：

EL1057E: No bean resolver registered in the context to resolve access to bean

1	EL1057E: No bean resolver registered in the context to resolve access to bean

但是如果我们是通过模板进行MVC页面渲染就不会报错，其实原因就是因为此时的context里缺少了spring的Beans的信息，通过spring mvc渲染时，框架会加入这些信息。那么手动渲染时我们也添加Beans的信息就可以了。

Context context = new Context();
context.setVariables(dataMap);

ThymeleafEvaluationContext tec = new ThymeleafEvaluationContext(applicationContext, null);
dataMap.put(ThymeleafEvaluationContext.THYMELEAF_EVALUATION_CONTEXT_CONTEXT_VARIABLE_NAME, tec);
templateEngine.process(templateName, context);

Context context = new Context();

context.setVariables(dataMap);

ThymeleafEvaluationContext tec = new ThymeleafEvaluationContext(applicationContext, null);

dataMap.put(ThymeleafEvaluationContext.THYMELEAF_EVALUATION_CONTEXT_CONTEXT_VARIABLE_NAME, tec);

templateEngine.process(templateName, context);

此时在进行渲染就正常了。

如果想更接近 Spring MVC 解析逻辑的，参考如代码：

@RequestMapping(value = "/uploadApk", produces = "text/javascript")
@ResponseBody
public String fragUploadApk(@NonNull final HttpServletRequest request, @NonNull final HttpServletResponse response) {        
    final WebContext context = new WebContext(request, response, request.getServletContext(), request.getLocale());

    # 此处使用 Spring MVC 默认的 FormattingConversionService.class 完成对数据的格式化（Springboot 2.7.11)
    final FormattingConversionService conversionService = applicationContext.getBean(FormattingConversionService.class);
    final ThymeleafEvaluationContext thymeleafEvaluationContext = new ThymeleafEvaluationContext(requireApplicationContext(), conversionService);
    context.setVariable(ThymeleafEvaluationContext.THYMELEAF_EVALUATION_CONTEXT_CONTEXT_VARIABLE_NAME, thymeleafEvaluationContext);
    templateEngine.process(templateName, context);
}

@RequestMapping(value = "/uploadApk", produces = "text/javascript")

@ResponseBody

public String fragUploadApk(@NonNull final HttpServletRequest request, @NonNull final HttpServletResponse response) {

final WebContext context = new WebContext(request, response, request.getServletContext(), request.getLocale());

# 此处使用 Spring MVC 默认的 FormattingConversionService.class 完成对数据的格式化（Springboot 2.7.11)

final FormattingConversionService conversionService = applicationContext.getBean(FormattingConversionService.class);

final ThymeleafEvaluationContext thymeleafEvaluationContext = new ThymeleafEvaluationContext(requireApplicationContext(), conversionService);

context.setVariable(ThymeleafEvaluationContext.THYMELEAF_EVALUATION_CONTEXT_CONTEXT_VARIABLE_NAME, thymeleafEvaluationContext);

templateEngine.process(templateName, context);

}

参考链接

Spring Boot启动报错-"类文件具有错误的版本 61.0, 应为 52.0"

项目使用的 Spring Boot 升级到 3.0.5 版本

编译的时候报错如下：

Error:(5, 32) java: 无法访问org.springframework.lang.NonNull
  错误的类文件: /Users/xxxx/.m2/repository/org/springframework/spring-core/6.0.7/spring-core-6.0.7.jar(org/springframework/lang/NonNull.class)
    类文件具有错误的版本 61.0, 应为 52.0
    请删除该文件或确保该文件位于正确的类路径子目录中。

Error:(5, 32) java: 无法访问org.springframework.lang.NonNull

错误的类文件: /Users/xxxx/.m2/repository/org/springframework/spring-core/6.0.7/spring-core-6.0.7.jar(org/springframework/lang/NonNull.class)

类文件具有错误的版本 61.0, 应为 52.0

请删除该文件或确保该文件位于正确的类路径子目录中。

或者：

OpenJDK 64-Bit Server VM warning: Options -Xverify:none and -noverify were deprecated in JDK 13 and will likely be removed in a future release.
Connected to the target VM, address: '127.0.0.1:54101', transport: 'socket'
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/springframework/boot/SpringApplication has been compiled by a more recent version of the Java Runtime (class file version 61.0), this version of the Java Runtime only recognizes class file versions up to 58.0
	at java.base/java.lang.ClassLoader.defineClass1(Native Method)
	at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:1017)
	at java.base/java.security.SecureClassLoader.defineClass(SecureClassLoader.java:151)
	at java.base/jdk.internal.loader.BuiltinClassLoader.defineClass(BuiltinClassLoader.java:821)
	at java.base/jdk.internal.loader.BuiltinClassLoader.findClassOnClassPathOrNull(BuiltinClassLoader.java:719)
	at java.base/jdk.internal.loader.BuiltinClassLoader.loadClassOrNull(BuiltinClassLoader.java:642)
	at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:600)
	at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
	at com.xxx.xxx.xxx.MainServiceApplication.main(MainServiceApplication.java:12)
Disconnected from the target VM, address: '127.0.0.1:54101', transport: 'socket'

OpenJDK 64-Bit Server VM warning: Options -Xverify:none and -noverify were deprecated in JDK 13 and will likely be removed in a future release.

Connected to the target VM, address: '127.0.0.1:54101', transport: 'socket'

Exception in thread "main" java.lang.UnsupportedClassVersionError: org/springframework/boot/SpringApplication has been compiled by a more recent version of the Java Runtime (class file version 61.0), this version of the Java Runtime only recognizes class file versions up to 58.0

at java.base/java.lang.ClassLoader.defineClass1(Native Method)

at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:1017)

at java.base/java.security.SecureClassLoader.defineClass(SecureClassLoader.java:151)

at java.base/jdk.internal.loader.BuiltinClassLoader.defineClass(BuiltinClassLoader.java:821)

at java.base/jdk.internal.loader.BuiltinClassLoader.findClassOnClassPathOrNull(BuiltinClassLoader.java:719)

at java.base/jdk.internal.loader.BuiltinClassLoader.loadClassOrNull(BuiltinClassLoader.java:642)

at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:600)

at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)

at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)

at com.xxx.xxx.xxx.MainServiceApplication.main(MainServiceApplication.java:12)

Disconnected from the target VM, address: '127.0.0.1:54101', transport: 'socket'

原因

SpringBoot 使用了 3.0 或者 3.0 以上，因为 Spring 官方发布从 Spring 6 以及 SprinBoot 3.0 开始最低支持 JDK17，所以仅需将 SpringBoot 版本降低为 3.0 以下即可。

参考链接

mybaties连接sqlite，并读取blob类型数据时，报错 java.sql.SQLFeatureNotSupportedException

java.sql.SQLException: not implemented by SQLite JDBC driver

1	java.sql.SQLException: not implemented by SQLite JDBC driver

错误,或者如下错误：

2021-06-03 09:25:20.435 ERROR 15643 --- [nio-8080-exec-7] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.apache.ibatis.exceptions.PersistenceException: 
### Error querying database.  Cause: org.apache.ibatis.executor.result.ResultMapException: Error attempting to get column 'appIcon' from result set.  Cause: java.sql.SQLFeatureNotSupportedException
### The error may exist in xxxx.java (best guess)
### The error may involve xxx.select
### The error occurred while handling results
### SQL: SELECT * FROM xxx WHERE id=?
### Cause: org.apache.ibatis.executor.result.ResultMapException: Error attempting to get column 'appIcon' from result set.  Cause: java.sql.SQLFeatureNotSupportedException] with root cause

2021-06-03 09:25:20.435 ERROR 15643 --- [nio-8080-exec-7] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.apache.ibatis.exceptions.PersistenceException:

### Error querying database. Cause: org.apache.ibatis.executor.result.ResultMapException: Error attempting to get column 'appIcon' from result set. Cause: java.sql.SQLFeatureNotSupportedException

### The error may exist in xxxx.java (best guess)

### The error may involve xxx.select

### The error occurred while handling results

### SQL: SELECT * FROM xxx WHERE id=?

### Cause: org.apache.ibatis.executor.result.ResultMapException: Error attempting to get column 'appIcon' from result set. Cause: java.sql.SQLFeatureNotSupportedException] with root cause

场景：
具体需求，要求像springboot连接mysql或者pgsql数据库一样，在application配置文件中配置sqlite数据库信息，并实现对blob类型数据（我们的库中有该类型的数据）的读写，按照平常一样写好controller、service、dao、mapper.xml后，执行查询操作后报错

原因分析：
sqlite的driver中，JDBC4ResultSet没有实现以下接口：

public Blob getBlob(int col)
throws SQLException { throw unused(); }
public Blob getBlob(String col)
throws SQLException { throw unused(); }

public Blob getBlob(int col)

throws SQLException { throw unused(); }

public Blob getBlob(String col)

throws SQLException { throw unused(); }

而是直接抛出了异常。
解决方法：
mapper.xml中该字段的设置：

<select id="queryByList" resultMap="queryBaseResultMap">
    select * from my_blob 
</select>
<resultMap id="queryBaseResultMap" type="com.wx.model.MyBlob" >
    <id column="Id" property="id" jdbcType="INTEGER" />
    <result column="blob" property="blob" typeHandler="com.wx.handler.BlobTypeHandler"/> 
</resultMap>

select * from my_blob

</select>

</resultMap>

即blob字段加个typeHandler属性。
然后自定义一个BlobTypeHandler处理类：

public class BlobTypeHandler extends BaseTypeHandler<byte[]> {

    @Override
    public void setNonNullParameter(PreparedStatement ps, int i, byte[] parameter, JdbcType jdbcType) throws SQLException {
        ps.setBytes(i, parameter);
    }

    @Override
    public byte[] getNullableResult(ResultSet rs, String columnName) throws SQLException {
        return rs.getBytes(columnName);
    }

    @Override
    public byte[] getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
        return rs.getBytes(columnIndex);
    }

    @Override
    public byte[] getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
        return cs.getBytes(columnIndex);
    }
}

public class BlobTypeHandler extends BaseTypeHandler<byte[]> {

@Override

public void setNonNullParameter(PreparedStatement ps, int i, byte[] parameter, JdbcType jdbcType) throws SQLException {

ps.setBytes(i, parameter);

}

@Override

public byte[] getNullableResult(ResultSet rs, String columnName) throws SQLException {

return rs.getBytes(columnName);

}

@Override

public byte[] getNullableResult(ResultSet rs, int columnIndex) throws SQLException {

return rs.getBytes(columnIndex);

}

@Override

public byte[] getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {

return cs.getBytes(columnIndex);

}

注意：实体类中blob字段类型是byte[]。

参考链接

mybaties连接sqlite，并读取blob类型数据时，报 java.sql.SQLException: not implemented by SQLite JDBC driver错误

spring boot设置favicon，favicon不生效，不成功，不起作用

Favicon配置

默认的Favicon图标

关闭默认图标
在application.properties中添加：

spring.mvc.favicon.enabled=false

1	spring.mvc.favicon.enabled=false

或者（我这个有效果）：

spring.favicon.enabled = false

1	spring.favicon.enabled = false

效果具体原因：https://jira.spring.io/browse/SPR-12851

spring boot设置favicon，favicon不生效，不成功，不起作用

springboot显示的是一片叶子，我们如何使用自己的favicon呢？

1.将favicon.icon放到resources目录下例如：/public,/static等等

2.完成上面的步骤还不能显示，还需在你的页面的head标签添加代码

<head>
    <meta charset="UTF-8">
    <title>登录</title>
    <link rel="shortcut icon" th:href="@{/favicon.ico}" type="image/x-icon"/>
    <link rel="icon" th:href="@{/favicon.ico}" type="image/x-icon"/>
    <link rel="bookmark" th:href="@{/favicon.ico}" type="image/x-icon"/>
</head>

<head>

</head>

3.注意我使用的thymeleaf所以是以上代码片段如果你不是请这样添加

<head>
    <meta charset="UTF-8">
    <title>登录</title>
    <link href="/favicon.ico" rel="shortcut icon" type="image/x-icon"/>
    <link href="/favicon.ico" rel="icon" type="image/x-icon"/>
    <link href="/favicon.ico" rel="bookmark" type="image/x-icon"/>
</head>

<head>

</head>

参考链接

spring boot设置favicon，favicon不生效，不成功，不起作用

Spring Boot+MyBatis+SQLite配置

Spring Boot+MyBatis+SQLite配置例子参考下面

继续阅读Spring Boot+MyBatis+SQLite配置

HttpClient利用MultipartEntityBuilder取代MultipartEntity上传图片文件到服务器

注意：在HttpClient4.3之后，原来的上传文件方法MultipartEntity已经不建议使用，现替换成新的httpmime下面的MultipartEntityBuilder。

需要添加httpclient-4.5.jar、httpmime-4.5.jar两个包

maven添加：

        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpmime</artifactId>
            <version>4.5</version>
        </dependency>
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.5</version>
        </dependency>

<groupId>org.apache.httpcomponents</groupId>

<artifactId>httpmime</artifactId>

</dependency>

<groupId>org.apache.httpcomponents</groupId>

<artifactId>httpclient</artifactId>

</dependency>

下面我们对比一下MultipartEntity和MultipartEntityBuilder的使用区别：

MultipartEntityBuilder：

             //传入参数可以为file或者filePath，在此处做转换
            File file = new File(filePath);
            CloseableHttpClient httpClient = HttpClients.createDefault();
            CloseableHttpResponse httpResponse = null;
            HttpPost httppost = new HttpPost(url);
            MultipartEntityBuilder builder = MultipartEntityBuilder.create();
            //设置浏览器兼容模式
            builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);
            //设置请求的编码格式
            builder.setCharset(Consts.UTF_8);
            builder.setContentType(ContentType.MULTIPART_FORM_DATA);
            //添加文件
            builder.addBinaryBody("file", file);
            HttpEntity reqEntity = builder.build();
            httppost.setEntity(reqEntity);

            httpResponse = httpClient.execute(httppost);

//传入参数可以为file或者filePath，在此处做转换

File file = new File(filePath);

CloseableHttpClient httpClient = HttpClients.createDefault();

CloseableHttpResponse httpResponse = null;

HttpPost httppost = new HttpPost(url);

MultipartEntityBuilder builder = MultipartEntityBuilder.create();

//设置浏览器兼容模式

builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);

//设置请求的编码格式

builder.setCharset(Consts.UTF_8);

builder.setContentType(ContentType.MULTIPART_FORM_DATA);

//添加文件

builder.addBinaryBody("file", file);

HttpEntity reqEntity = builder.build();

httppost.setEntity(reqEntity);

httpResponse = httpClient.execute(httppost);

MultipartEntity：

            //传入参数可以为file或者filePath，在此处做转换
            File file = new File(filePath);
            CloseableHttpClient httpClient = HttpClients.createDefault();
            CloseableHttpResponse httpResponse = null;
            HttpPost httppost = new HttpPost(url);
            FileBody filebody = new FileBody(file);
            MultipartEntity entity = new MultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE, null,
                    Charset.forName("UTF-8"));
            entity.addPart("file", filebody);
            httppost.setEntity(entity);

//传入参数可以为file或者filePath，在此处做转换

File file = new File(filePath);

CloseableHttpClient httpClient = HttpClients.createDefault();

CloseableHttpResponse httpResponse = null;

HttpPost httppost = new HttpPost(url);

FileBody filebody = new FileBody(file);

MultipartEntity entity = new MultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE, null,

Charset.forName("UTF-8"));

entity.addPart("file", filebody);

httppost.setEntity(entity);

直接上替换后的测试代码：

package com.test.util;
import net.sf.json.JSONObject;
import org.apache.commons.lang.StringUtils;
import org.apache.http.Consts;
import org.apache.http.HttpEntity;
import org.apache.http.HttpStatus;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.mime.HttpMultipartMode;
import org.apache.http.entity.mime.MultipartEntityBuilder;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Iterator;
import java.util.Map;

public class HttpPostUploadUtil {

    /**
     * @param args
     */
    public static void main(String[] args) {
        String filePath = "D:\\Test\\0.jpg";
        String url = "http://127.0.0.1:8080/FastFds";
        //调用上传方法
        String backInfo = uploadPost(url, filePath);
        if(StringUtils.isNotBlank(backInfo)){
            //转json数据
            JSONObject json = JSONObject.fromObject(backInfo);
            if(!json.isEmpty()){
                //数据处理
                String value = json.getString("test");
                System.out.println(value);
            }
        }
    }

    /**
     * 上传图片/文件
     * @param url
     * @param filePath
     * @return String 用于转json或者其他信息
     */
    public static String uploadPost(String url, String filePath)  {
        String requestJson = "";
        //传入参数可以为file或者filePath，在此处做转换
        File file = new File(filePath);

        CloseableHttpClient httpClient = HttpClients.createDefault();
        CloseableHttpResponse httpResponse = null;
        try {
            HttpPost httppost = new HttpPost(url);
            MultipartEntityBuilder builder = MultipartEntityBuilder.create();
            //设置浏览器兼容模式
            builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);
            //设置请求的编码格式
            builder.setCharset(Consts.UTF_8);
            builder.setContentType(ContentType.MULTIPART_FORM_DATA);
            //添加文件
            builder.addBinaryBody("file", file);
            HttpEntity reqEntity = builder.build();
            httppost.setEntity(reqEntity);

            httpResponse = httpClient.execute(httppost);
            int backCode = httpResponse.getStatusLine().getStatusCode();
            if(backCode == HttpStatus.SC_OK){
                HttpEntity httpEntity = httpResponse.getEntity();
                byte[] json= EntityUtils.toByteArray(httpEntity);
                requestJson = new String(json, "UTF-8");
                //关闭流
                EntityUtils.consume(httpEntity);
                return requestJson;
            }
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            //释放资源
            try {
                httpClient.close();
                httpResponse.close();
            } catch (IOException e) {
                e.printStackTrace();
            }

        }
        return null;
    }
}

package com.test.util;

import net.sf.json.JSONObject;

import org.apache.commons.lang.StringUtils;

import org.apache.http.Consts;

import org.apache.http.HttpEntity;

import org.apache.http.HttpStatus;

import org.apache.http.client.ClientProtocolException;

import org.apache.http.client.methods.CloseableHttpResponse;

import org.apache.http.client.methods.HttpPost;

import org.apache.http.entity.ContentType;

import org.apache.http.entity.mime.HttpMultipartMode;

import org.apache.http.entity.mime.MultipartEntityBuilder;

import org.apache.http.impl.client.CloseableHttpClient;

import org.apache.http.impl.client.HttpClients;

import org.apache.http.util.EntityUtils;

import java.io.*;

import java.net.HttpURLConnection;

import java.net.URL;

import java.util.Iterator;

import java.util.Map;

public class HttpPostUploadUtil {

/**

* @param args

public static void main(String[] args) {

String filePath = "D:\\Test\\0.jpg";

String url = "http://127.0.0.1:8080/FastFds";

//调用上传方法

String backInfo = uploadPost(url, filePath);

if(StringUtils.isNotBlank(backInfo)){

//转json数据

JSONObject json = JSONObject.fromObject(backInfo);

if(!json.isEmpty()){

//数据处理

String value = json.getString("test");

System.out.println(value);

}

/**

* 上传图片/文件

* @param url

* @param filePath

* @return String 用于转json或者其他信息

public static String uploadPost(String url, String filePath) {

String requestJson = "";

//传入参数可以为file或者filePath，在此处做转换

File file = new File(filePath);

CloseableHttpClient httpClient = HttpClients.createDefault();

CloseableHttpResponse httpResponse = null;

try {

HttpPost httppost = new HttpPost(url);

MultipartEntityBuilder builder = MultipartEntityBuilder.create();

//设置浏览器兼容模式

builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);

//设置请求的编码格式

builder.setCharset(Consts.UTF_8);

builder.setContentType(ContentType.MULTIPART_FORM_DATA);

//添加文件

builder.addBinaryBody("file", file);

HttpEntity reqEntity = builder.build();

httppost.setEntity(reqEntity);

httpResponse = httpClient.execute(httppost);

int backCode = httpResponse.getStatusLine().getStatusCode();

if(backCode == HttpStatus.SC_OK){

HttpEntity httpEntity = httpResponse.getEntity();

byte[] json= EntityUtils.toByteArray(httpEntity);

requestJson = new String(json, "UTF-8");

//关闭流

EntityUtils.consume(httpEntity);

return requestJson;

}

} catch (ClientProtocolException e) {

e.printStackTrace();

} catch (IOException e) {

e.printStackTrace();

} finally {

//释放资源

try {

httpClient.close();

httpResponse.close();

} catch (IOException e) {

e.printStackTrace();

}

return null;

}

继续阅读HttpClient利用MultipartEntityBuilder取代MultipartEntity上传图片文件到服务器

Spring Boot实现异步任务

Spring Boot中的另外一个任务：异步任务。所谓异步任务，其实就是异步执行程序，有些时候遇到一些耗时的的任务，如果一直卡等待，肯定会影响其他程序的执行，所以就让这些程序需要以异步的方式去执行。那么下面就来介绍Spring Boot 如何实现异步任务。

一、使用注解@EnableAsync 开启异步调用方法

在application启动类中，加上@EnableAsync注解，Spring Boot 会自动扫描异步任务。

package com.weiz;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.scheduling.annotation.EnableScheduling;
import tk.mybatis.spring.annotation.MapperScan;

@SpringBootApplication
//扫描 mybatis mapper 包路径
@MapperScan(basePackages = "com.weiz.mapper")
//扫描 所有需要的包, 包含一些自用的工具类包 所在的路径
@ComponentScan(basePackages = {"com.weiz","org.n3r.idworker"})
//开启定时任务
@EnableScheduling
//开启异步调用方法
@EnableAsync
public class SpringBootStarterApplication {
    public static void main(String[] args) {
        SpringApplication.run(SpringBootStarterApplication.class, args);
    }

}

package com.weiz;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.context.annotation.ComponentScan;

import org.springframework.scheduling.annotation.EnableAsync;

import org.springframework.scheduling.annotation.EnableScheduling;

import tk.mybatis.spring.annotation.MapperScan;

@SpringBootApplication

//扫描 mybatis mapper 包路径

@MapperScan(basePackages = "com.weiz.mapper")

//扫描所有需要的包, 包含一些自用的工具类包所在的路径

@ComponentScan(basePackages = {"com.weiz","org.n3r.idworker"})

//开启定时任务

@EnableScheduling

//开启异步调用方法

@EnableAsync

public class SpringBootStarterApplication {

public static void main(String[] args) {

SpringApplication.run(SpringBootStarterApplication.class, args);

}

二、创建异步执行类，定义@Component及@Async组件

创建com.weiz.tasks包，在tasks包里增加AsyncTask 异步任务类，加上@Component 注解，然后在需要异步执行的方法前面加上@Async注解，这样Spring Boot容器扫描到相关异步方法之后，调用时就会将这些方法异步执行。

package com.weiz.tasks;

import java.util.concurrent.Future;

import org.springframework.scheduling.annotation.Async;
import org.springframework.scheduling.annotation.AsyncResult;
import org.springframework.stereotype.Component;

@Component
public class AsyncTask {
    
    @Async
    public Future<Boolean> doTask11() throws Exception {
        long start = System.currentTimeMillis();
        Thread.sleep(1000);
        long end = System.currentTimeMillis();
        System.out.println("任务1耗时:" + (end - start) + "毫秒");
        return new AsyncResult<>(true);
    }
    
    @Async
    public Future<Boolean> doTask22() throws Exception {
        long start = System.currentTimeMillis();
        Thread.sleep(700);
        long end = System.currentTimeMillis();
        System.out.println("任务2耗时:" + (end - start) + "毫秒");
        return new AsyncResult<>(true);
    }
    
    @Async
    public Future<Boolean> doTask33() throws Exception {
        long start = System.currentTimeMillis();
        Thread.sleep(600);
        long end = System.currentTimeMillis();
        System.out.println("任务3耗时:" + (end - start) + "毫秒");
        return new AsyncResult<>(true); 
    }
}

package com.weiz.tasks;

import java.util.concurrent.Future;

import org.springframework.scheduling.annotation.Async;

import org.springframework.scheduling.annotation.AsyncResult;

import org.springframework.stereotype.Component;

@Component

public class AsyncTask {

@Async

public Future<Boolean> doTask11() throws Exception {

long start = System.currentTimeMillis();

Thread.sleep(1000);

long end = System.currentTimeMillis();

System.out.println("任务1耗时:" + (end - start) + "毫秒");

return new AsyncResult<>(true);

}

@Async

public Future<Boolean> doTask22() throws Exception {

long start = System.currentTimeMillis();

Thread.sleep(700);

long end = System.currentTimeMillis();

System.out.println("任务2耗时:" + (end - start) + "毫秒");

return new AsyncResult<>(true);

}

@Async

public Future<Boolean> doTask33() throws Exception {

long start = System.currentTimeMillis();

Thread.sleep(600);

long end = System.currentTimeMillis();

System.out.println("任务3耗时:" + (end - start) + "毫秒");

return new AsyncResult<>(true);

}

说明：@Async 加上这个注解，就表示该方法是异步执行方法。

三、调用

创建一个DoTask调用类，我们看看这几个方法，是怎么执行的：

package com.weiz.tasks;

import java.util.concurrent.Future;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("tasks")
public class DoTask {

    @Autowired
    private AsyncTask asyncTask;

    @RequestMapping("test1")
    public String test1() throws Exception {

        long start = System.currentTimeMillis();

        Future<Boolean> a = asyncTask.doTask11();
        Future<Boolean> b = asyncTask.doTask22();
        Future<Boolean> c = asyncTask.doTask33();

        while (!a.isDone() || !b.isDone() || !c.isDone()) {
            if (a.isDone() && b.isDone() && c.isDone()) {
                break;
            }
        }

        long end = System.currentTimeMillis();

        String times = "任务全部完成，总耗时：" + (end - start) + "毫秒";
        System.out.println(times);

        return times;
    }
}

package com.weiz.tasks;

import java.util.concurrent.Future;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RestController;

@RestController

@RequestMapping("tasks")

public class DoTask {

@Autowired

private AsyncTask asyncTask;

@RequestMapping("test1")

public String test1() throws Exception {

long start = System.currentTimeMillis();

Future<Boolean> a = asyncTask.doTask11();

Future<Boolean> b = asyncTask.doTask22();

Future<Boolean> c = asyncTask.doTask33();

while (!a.isDone() || !b.isDone() || !c.isDone()) {

if (a.isDone() && b.isDone() && c.isDone()) {

break;

}

long end = System.currentTimeMillis();

String times = "任务全部完成，总耗时：" + (end - start) + "毫秒";

System.out.println(times);

return times;

}

继续阅读Spring Boot实现异步任务

SpringBoot如何实现一个实时更新的进度条的示例代码

前言

导入excel表格批量修改状态，期间如果发生错误则所有数据不成功，为了防止重复提交，做一个类似进度条的东东。

那么下面我会结合实际业务对这个功能进行分析和记录。

正文

思路

前端使用bootstrap，后端使用SpringBoot分布式到注册中心，原先的想法是导入表格后异步调用修改数据状态的方法，然后每次计算修改的进度然后存放在session中，前台jquery写定时任务访问获取session中的进度，更新进度条进度和百分比。但是这存在session在服务间不共享，跨域问题。那么换一个方式存放，存放在redis中，前台定时任务直接操作获取redis的数据。

实施

进度条

先来看一下bootstrap的进度条

<div class="progress progress-striped active">
  <div class="progress-bar progress-bar-success" role="progressbar"
     aria-valuenow="60" aria-valuemin="0" aria-valuemax="100"
     style="width: 40%;">
    40%
  </div>
</div>

<div class="progress-bar progress-bar-success" role="progressbar"

aria-valuenow="60" aria-valuemin="0" aria-valuemax="100"

style="width: 40%;">

40%

</div>

进度条更新主要更新style="width: 40%;"的值即可，div里面的40%可以省略，无非时看着明确。

可以考虑将进度条放入弹出层。

定时任务

//点击确认导入执行此方法
function bulkImportChanges() {
  //获取批量操作状态文件
  var files = $("#importChanges").prop("files");
  var changesFile = files[0];
  var formData = new FormData();
  formData.append("importFile",changesFile);
  $.ajax({
    type : 'post',
    url : "/risk/bulk***es",
    data : formData,
    processData : false,   //文件ajax上传要加这两个的，要不然上传不了
    contentType : false,   //
    success : function(obj) {
      //导入成功
      if (obj.rspCode == "00") {
        //定时任务获取redis导入修改进度
        var progress = "";
        var timingTask = setInterval(function(){
          $.ajax({
            type: 'post',
            url: "/risk/t***k",
            dataType : 'json',
            success: function(result) {
              progress = result.value;
              if (progress != "error"){
                var date = progress.substring(0,6);
                //这里更新进度条的进度和数据
                $(".progress-bar").width(parseFloat(date)+"%");
                $(".progress-bar").text(parseFloat(date)+"%");
              }
            }
          });
          //导入修改完成或异常（停止定时任务）
          if (parseInt(progress)==100 || progress == "error") {
            //清除定时执行
            clearInterval(timingTask);
            $.ajax({
              type: 'post',
              url: "/risk/de***ess",
              dataType : 'json',
              success: function(result) {
                $("#bulkImportChangesProcessor").hide();
                if (parseInt(progress) == 100) {
                  alert("批量导入修改状态成功");
                }
                if (progress == "error") {
                  alert("批量导入修改状态失败");
                }
                //获取最新数据
                window.location.href="/risk/re***ByParam" rel="external nofollow" rel="external nofollow" ;
              }
            });
          }
        }, 1000)
      }else {
        $("#bulkImportChangesProcessor").hide();
        alert(obj.rspMsg);
        window.location.href="/risk/re***ByParam" rel="external nofollow" rel="external nofollow" ;
      }
    }
  });
}

//点击确认导入执行此方法

function bulkImportChanges() {

//获取批量操作状态文件

var files = $("#importChanges").prop("files");

var changesFile = files[0];

var formData = new FormData();

formData.append("importFile",changesFile);

$.ajax({

type : 'post',

url : "/risk/bulk***es",

data : formData,

processData : false, //文件ajax上传要加这两个的，要不然上传不了

contentType : false, //

success : function(obj) {

//导入成功

if (obj.rspCode == "00") {

//定时任务获取redis导入修改进度

var progress = "";

var timingTask = setInterval(function(){

$.ajax({

type: 'post',

url: "/risk/t***k",

dataType : 'json',

success: function(result) {

progress = result.value;

if (progress != "error"){

var date = progress.substring(0,6);

//这里更新进度条的进度和数据

$(".progress-bar").width(parseFloat(date)+"%");

$(".progress-bar").text(parseFloat(date)+"%");

}

});

//导入修改完成或异常（停止定时任务）

if (parseInt(progress)==100 || progress == "error") {

//清除定时执行

clearInterval(timingTask);

$.ajax({

type: 'post',

url: "/risk/de***ess",

dataType : 'json',

success: function(result) {

$("#bulkImportChangesProcessor").hide();

if (parseInt(progress) == 100) {

alert("批量导入修改状态成功");

}

if (progress == "error") {

alert("批量导入修改状态失败");

}

//获取最新数据

window.location.href="/risk/re***ByParam" rel="external nofollow" rel="external nofollow" ;

}

});

}

}, 1000)

}else {

$("#bulkImportChangesProcessor").hide();

alert(obj.rspMsg);

window.location.href="/risk/re***ByParam" rel="external nofollow" rel="external nofollow" ;

}

});

}

解释：点击确认导入文件后成功后开启定时任务每一秒(一千毫秒)访问一次后台获取redis存放的进度，返回更新进度条，如果更新完成或者更新失败（根据后台返回的数据决定）则停止定时任务显示相应的信息并刷新页面。获取最新数据。

后台控制层

/**
 * 退单管理批量修改状态导入文件
 * @param importFile
 * @return
 */
 @ResponseBody
 @RequestMapping("/bulk***es")
 public Map<String,Object> bulk***es(MultipartFile importFile){
   log.info("退单管理批量修改状态导入文件，传入参数："+importFile);
 Map<String,Object> map = new HashMap<>();
 List<Bulk***esEntity> fromExcel = null;
 try{
      //使用工具类导入转成list
  String[] header = {"sy***um","t***mt","ha***ult","re***nd","sy***nd","r**k"};
  fromExcel = importExcelUtil.importDataFromExcel(importFile, header, BulkImportChangesEntity.class);
  if (fromExcel.size()==0){
  map.put("rspCode","99");
  map.put("rspMsg","导入数据不能为空");
  return map;
  }
 }catch (Exception e){
  map.put("rspCode","99");
  map.put("rspMsg","导入操作表失败,请注意数据列格式");
  return map;
 }
 try {
  //这里会对list集合中的数据进行处理

  log.info("调用服务开始，参数："+JSON.toJSONString(fromExcel));
  //String url = p4_zuul_url+"/***/ri***eat/bu***nges";
  String url = p4_zuul_url+"/***-surpass/ri***eat/bu***nges";
  String result = HttpClientUtil.doPost(url,JSON.toJSONString(fromExcel));
  log.info("调用服务结束，返回数据："+result);
  if (result != null){
  map = JSONObject.parseObject(result, Map.class);
  log.info("批量修改状态导入："+JSON.toJSONString(map));
  }
 }catch (Exception e){
  map.put("rspCode","99");
  map.put("rspMsg","导入操作表失败");
  log.info("bu***es exception",e);
  return map;
 }
 return map;
 }

 /**
 * 获取退单管理批量修改状态导入文件进度条进度
 * @return
 */
 @ResponseBody
 @RequestMapping("/t***sk")
 public Map<String,Object> t***sk(){
 Map<String,Object> map = new HashMap<>();
    //获取redis值
 String progress = HttpClientUtil.doGet(
  p4_zuul_url + "/" + p4_redis + "/redis***ler/get?key=progressSchedule");
 if (progress != null){
  map = JSONObject.parseObject(progress, Map.class);
  log.info("进度条进度："+JSON.toJSONString(map));
  map.put("progressSchedule",progress);
 }else {
  HttpClientUtil.doGet(
   p4_zuul_url + "/" + p4_redis + "/redis***ler/del?key=progressSchedule");
 }
 return map;
 }

 /**
 * 清除redis进度条进度
 * @return
 */
 @ResponseBody
 @RequestMapping("/de***ess")
 public Map<String,Object> de***ess(){
 Map<String,Object> map = new HashMap<>();
 String progress = HttpClientUtil.doGet(
  p4_zuul_url + "/" + p4_redis + "/redis***ler/del?key=progressSchedule");
 if (progress != null){
  map = JSONObject.parseObject(progress, Map.class);
  log.info("返回数据："+JSON.toJSONString(map));
 }
 return map;
 }

/**

* 退单管理批量修改状态导入文件

* @param importFile

* @return

@ResponseBody

@RequestMapping("/bulk***es")

public Map<String,Object> bulk***es(MultipartFile importFile){

log.info("退单管理批量修改状态导入文件，传入参数："+importFile);

Map<String,Object> map = new HashMap<>();

List<Bulk***esEntity> fromExcel = null;

try{

//使用工具类导入转成list

String[] header = {"sy***um","t***mt","ha***ult","re***nd","sy***nd","r**k"};

fromExcel = importExcelUtil.importDataFromExcel(importFile, header, BulkImportChangesEntity.class);

if (fromExcel.size()==0){

map.put("rspCode","99");

map.put("rspMsg","导入数据不能为空");

return map;

}

}catch (Exception e){

map.put("rspCode","99");

map.put("rspMsg","导入操作表失败,请注意数据列格式");

return map;

}

try {

//这里会对list集合中的数据进行处理

log.info("调用服务开始，参数："+JSON.toJSONString(fromExcel));

//String url = p4_zuul_url+"/***/ri***eat/bu***nges";

String url = p4_zuul_url+"/***-surpass/ri***eat/bu***nges";

String result = HttpClientUtil.doPost(url,JSON.toJSONString(fromExcel));

log.info("调用服务结束，返回数据："+result);

if (result != null){

map = JSONObject.parseObject(result, Map.class);

log.info("批量修改状态导入："+JSON.toJSONString(map));

}

}catch (Exception e){

map.put("rspCode","99");

map.put("rspMsg","导入操作表失败");

log.info("bu***es exception",e);

return map;

}

return map;

}

/**

* 获取退单管理批量修改状态导入文件进度条进度

* @return

@ResponseBody

@RequestMapping("/t***sk")

public Map<String,Object> t***sk(){

Map<String,Object> map = new HashMap<>();

//获取redis值

String progress = HttpClientUtil.doGet(

p4_zuul_url + "/" + p4_redis + "/redis***ler/get?key=progressSchedule");

if (progress != null){

map = JSONObject.parseObject(progress, Map.class);

log.info("进度条进度："+JSON.toJSONString(map));

map.put("progressSchedule",progress);

}else {

HttpClientUtil.doGet(

p4_zuul_url + "/" + p4_redis + "/redis***ler/del?key=progressSchedule");

}

return map;

}

/**

* 清除redis进度条进度

* @return

@ResponseBody

@RequestMapping("/de***ess")

public Map<String,Object> de***ess(){

Map<String,Object> map = new HashMap<>();

String progress = HttpClientUtil.doGet(

p4_zuul_url + "/" + p4_redis + "/redis***ler/del?key=progressSchedule");

if (progress != null){

map = JSONObject.parseObject(progress, Map.class);

log.info("返回数据："+JSON.toJSONString(map));

}

return map;

}

导入时调用第一个bulk***es方法，定时任务调用t***sk方法，导入完成或发生错误调用de***ess方法删除redis数据，避免占用资源。

服务层

@Async//开启异步
 @Transactional(rollbackFor = Exception.class)//事务回滚级别
 @Override
 public void bulkImportChanges(List<BulkImportChangesParam> list) {
 //初始化进度
 Double progressBarSchedule = 0.0;
 redisClient.set("progressSchedule", progressBarSchedule + "");//存redis
 try {
  for (int i = 1; i <= list.size(); i++) {
  RiskRetreatEntity entity = riskRetreatMapper.selectRetreatListBySysRefNum(list.get(i-1).getSysRefNum());
  if (entity == null){
   //查询结果为空直接进行下次循环不抛出
   continue;
  }
  //实体封装
        ···
        //更新
  riskRetreatMapper.updateRetreatByImport(entity);
  //计算修改进度并存放redis保存(1.0 / list.size())为一条数据进度
  progressBarSchedule = (1.0 / list.size()) * i*100;
  redisClient.set("progressSchedule", progressBarSchedule+"");
  if (i==list.size()){
   redisClient.set("progressSchedule", "100");
  }
  }
 }catch (Exception e){
  //当发生错误则清除缓存直接抛出回滚
  redisClient.set("progressSchedule","error");
  log.info("导入更新错误，回滚");
  log.info("bulkImportChanges exception:",e);
  throw e;
 }
 }

@Async//开启异步

@Transactional(rollbackFor = Exception.class)//事务回滚级别

@Override

public void bulkImportChanges(List<BulkImportChangesParam> list) {

//初始化进度

Double progressBarSchedule = 0.0;

redisClient.set("progressSchedule", progressBarSchedule + "");//存redis

try {

for (int i = 1; i <= list.size(); i++) {

RiskRetreatEntity entity = riskRetreatMapper.selectRetreatListBySysRefNum(list.get(i-1).getSysRefNum());

if (entity == null){

//查询结果为空直接进行下次循环不抛出

continue;

}

//实体封装

···

//更新

riskRetreatMapper.updateRetreatByImport(entity);

//计算修改进度并存放redis保存(1.0 / list.size())为一条数据进度

progressBarSchedule = (1.0 / list.size()) * i*100;

redisClient.set("progressSchedule", progressBarSchedule+"");

if (i==list.size()){

redisClient.set("progressSchedule", "100");

}

}catch (Exception e){

//当发生错误则清除缓存直接抛出回滚

redisClient.set("progressSchedule","error");

log.info("导入更新错误，回滚");

log.info("bulkImportChanges exception:",e);

throw e;

}

每更新一条数据存放进度，当发生错误则进行回滚。如果开启异步则需要在启动类添加注解@EnableAsync。

@EnableAsync
···//其他注解
public class Application {
  public static void main(String[] args) {
    SpringApplication.run(Application.class, args);
  }
}

@EnableAsync

···//其他注解

public class Application {

public static void main(String[] args) {

SpringApplication.run(Application.class, args);

}

继续阅读SpringBoot如何实现一个实时更新的进度条的示例代码