14-SpringBoot——Spring MVC基础-自定义HttpMessageConverter

Spring MVC基础-自定义HttpMessageConverter

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【博文目录>>>】

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【项目源码>>>】

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【自定义HttpMessageConverter】

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HttpMessageConveter 是用来处理request 和response 里的数据的。Spring 为我们内置了大量的HttpMessageConverter，例如， MappingJackson2HttpMessageConverter 、StringHttpMessageConverter 等。我们实现一个自定义的HttpMessageConverter，他将接收以“-”号连接的数据，将数据转换成自定义的对象。

【代码实现】

package com.example.spring.framework.converter.domain;/** * Author: 王俊超 * Date: 2017-07-11 22:07 * All Rights Reserved !!! */public class DemoObj {    private Long id;    private String name;    public DemoObj() {        super();    }    public DemoObj(Long id, String name) {        super();        this.id = id;        this.name = name;    }    public Long getId() {        return id;    }    public void setId(Long id) {        this.id = id;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }}

package com.example.spring.framework.converter.controller;import com.example.spring.framework.converter.domain.DemoObj;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestBody;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import org.springframework.web.bind.annotation.ResponseBody;/** * Author: 王俊超 * Date: 2017-07-13 07:56 * All Rights Reserved !!! */@Controllerpublic class ConverterController {    /**     * 指定返回的媒体类型为我们自定义的媒体类型application/x惆wisely     */    @RequestMapping(method = RequestMethod.POST, value = "/convert",            produces = "application/x-wisely")    public @ResponseBody    DemoObj converter(@RequestBody DemoObj obj) {        return obj;    }}

package com.example.spring.framework.converter.config;import com.example.spring.framework.converter.MyMessageConverter;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.ComponentScan;import org.springframework.context.annotation.Configuration;import org.springframework.http.converter.HttpMessageConverter;import org.springframework.web.servlet.config.annotation.EnableWebMvc;import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;import org.springframework.web.servlet.view.InternalResourceViewResolver;import org.springframework.web.servlet.view.JstlView;import java.util.List;/** * Author: 王俊超 * Date: 2017-07-12 07:22 * All Rights Reserved !!! */@Configuration@EnableWebMvc@ComponentScan("com.example.spring.framework.converter")public class MyMvcConfig extends WebMvcConfigurerAdapter {    @Bean    public InternalResourceViewResolver viewResolver() {        InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();        viewResolver.setPrefix("/WEB-INF/classes/views/");        viewResolver.setSuffix(".jsp");        viewResolver.setViewClass(JstlView.class);        return viewResolver;    }    @Override    public void addResourceHandlers(ResourceHandlerRegistry registry) {        registry.addResourceHandler("/assets/**").addResourceLocations("classpath:/assets/");        super.addResourceHandlers(registry);    }    @Override    public void addViewControllers(ViewControllerRegistry registry) {        registry.addViewController("/converter").setViewName("/converter");    }    /**     * 配置自定义的HttpMessageConverter 的Bean ，在Spring MVC 里注册HttpMessageConverter有两个方法：     * 1、configureMessageConverters ：重载会覆盖掉Spring MVC 默认注册的多个HttpMessageConverter     * 2、extendMessageConverters ：仅添加一个自定义的HttpMessageConverter ，不覆盖默认注册的HttpMessageConverter     * 在这里重写extendMessageConverters     */    @Override    public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {        converters.add(converter());    }    @Bean    public MyMessageConverter converter() {        return new MyMessageConverter();    }}

package com.example.spring.framework.converter;import com.example.spring.framework.converter.domain.DemoObj;import org.springframework.http.HttpInputMessage;import org.springframework.http.HttpOutputMessage;import org.springframework.http.MediaType;import org.springframework.http.converter.AbstractHttpMessageConverter;import org.springframework.http.converter.HttpMessageNotReadableException;import org.springframework.http.converter.HttpMessageNotWritableException;import org.springframework.util.StreamUtils;import java.io.IOException;import java.nio.charset.Charset;/** * 继承AbstractHttpMessageConverter 接口来实现自定义的HttpMessageConverter * Author: 王俊超 * Date: 2017-07-13 07:44 * All Rights Reserved !!! */public class MyMessageConverter extends AbstractHttpMessageConverter<DemoObj> {    public MyMessageConverter() {        // 新建一个我们自定义的媒体类型application/x-wisely        super(new MediaType("application", "x-wisely", Charset.forName("UTF-8")));    }    @Override    protected boolean supports(Class<?> clazz) {        // 表明本HttpMessageConverter 只处理DemoObj 这个类。        return DemoObj.class.isAssignableFrom(clazz);    }    /**     * 重写readlntenal 方法，处理请求的数据。代码表明我们处理由“四”隔开的数据，并转成 DemoObj 的对象。     */    @Override    protected DemoObj readInternal(Class<? extends DemoObj> clazz,            HttpInputMessage inputMessage) throws IOException,            HttpMessageNotReadableException {        String temp = StreamUtils.copyToString(inputMessage.getBody(), Charset.forName("UTF-8"));        String[] tempArr = temp.split("-");        return new DemoObj(new Long(tempArr[0]), tempArr[1]);    }    /**     * 重写writeInternal ，处理如何输出数据到response。此例中，我们在原样输出前面加上"hello ："。     */    @Override    protected void writeInternal(DemoObj demoObj,            HttpOutputMessage outputMessage)            throws IOException, HttpMessageNotWritableException {        String out = "hello: " + demoObj.getId() + "-" + demoObj.getName();        outputMessage.getBody().write(out.getBytes());    }}

package com.example.spring.framework.converter;import com.example.spring.framework.converter.config.MyMvcConfig;import org.springframework.web.WebApplicationInitializer;import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;import org.springframework.web.servlet.DispatcherServlet;import javax.servlet.ServletContext;import javax.servlet.ServletException;import javax.servlet.ServletRegistration;/** * Author: 王俊超 * Date: 2017-07-11 21:51 * All Rights Reserved !!! */public class WebInitializer implements WebApplicationInitializer {    @Override    public void onStartup(ServletContext servletContext) throws ServletException {        AnnotationConfigWebApplicationContext ctx = new AnnotationConfigWebApplicationContext();        ctx.register(MyMvcConfig.class);        ctx.setServletContext(servletContext);        ServletRegistration.Dynamic servlet = servletContext.addServlet("dispatcher",                new DispatcherServlet(ctx));        servlet.addMapping("/");        servlet.setLoadOnStartup(1);    }}

<%@ page language="java" contentType="text/html; charset=UTF-8"         pageEncoding="UTF-8" %><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head>    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">    <title>HttpMessageConverter Demo</title></head><body><div id="resp"></div><input type="button" onclick="req();" value="请求"/><script src="assets/assets.js/jquery.assets.js" type="text/javascript"></script><script>    function req() {        $.ajax({            url: "convert",            data: "1-wangjunchao", // 注意这里的数据格式，后台处理按此格式处理，用“-”隔开。            type: "POST",            contentType: "application/x-wisely", // contentType 设置的媒体类型是我们自定义的application/x-wisely            success: function (data) {                $("#resp").html(data);            }        });    }</script></body></html>