自定义Spring Boot 内容协商

47.Spring-Boot-Content-Negotiation/pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>2.1.0.RELEASE</version>
+        <relativePath/> <!-- lookup parent from repository -->
+    </parent>
+    <groupId>com.example</groupId>
+    <artifactId>demo</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>demo</name>
+    <description>Demo project for Spring Boot</description>
+
+    <properties>
+        <java.version>1.8</java.version>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

47.Spring-Boot-Content-Negotiation/src/main/java/com/example/demo/DemoApplication.java

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+package com.example.demo;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class DemoApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(DemoApplication.class, args);
+    }
+
+}

47.Spring-Boot-Content-Negotiation/src/main/java/com/example/demo/config/WebConfigurer.java

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+package com.example.demo.config;
+
+import com.example.demo.converter.PropertiesHttpMessageConverter;
+import com.example.demo.handler.PropertiesHandlerMethodReturnValueHandler;
+import com.example.demo.resolver.PropertiesHandlerMethodArgumentResolver;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.http.converter.HttpMessageConverter;
+import org.springframework.web.method.support.HandlerMethodArgumentResolver;
+import org.springframework.web.method.support.HandlerMethodReturnValueHandler;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+import org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter;
+
+import javax.annotation.PostConstruct;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * @author MrBird
+ */
+@Configuration
+public class WebConfigurer implements WebMvcConfigurer {
+
+
+    @Autowired
+    private RequestMappingHandlerAdapter requestMappingHandlerAdapter;
+
+    @PostConstruct
+    public void init() {
+        // 获取当前 RequestMappingHandlerAdapter 所有的 ArgumentResolver对象
+        List<HandlerMethodArgumentResolver> argumentResolvers = requestMappingHandlerAdapter.getArgumentResolvers();
+        List<HandlerMethodArgumentResolver> newArgumentResolvers = new ArrayList<>(argumentResolvers.size() + 1);
+        // 添加 PropertiesHandlerMethodArgumentResolver 到集合第一个位置
+        newArgumentResolvers.add(0, new PropertiesHandlerMethodArgumentResolver());
+        // 将原 ArgumentResolver 添加到集合中
+        newArgumentResolvers.addAll(argumentResolvers);
+        // 重新设置 ArgumentResolver对象集合
+        requestMappingHandlerAdapter.setArgumentResolvers(newArgumentResolvers);
+
+        // 获取当前 RequestMappingHandlerAdapter 所有的 returnValueHandlers对象
+        List<HandlerMethodReturnValueHandler> returnValueHandlers = requestMappingHandlerAdapter.getReturnValueHandlers();
+        List<HandlerMethodReturnValueHandler> newReturnValueHandlers = new ArrayList<>(returnValueHandlers.size() + 1);
+        // 添加 PropertiesHandlerMethodReturnValueHandler 到集合第一个位置
+        newReturnValueHandlers.add(0, new PropertiesHandlerMethodReturnValueHandler());
+        // 将原 returnValueHandlers 添加到集合中
+        newReturnValueHandlers.addAll(returnValueHandlers);
+        // 重新设置 ReturnValueHandlers对象集合
+        requestMappingHandlerAdapter.setReturnValueHandlers(newReturnValueHandlers);
+    }
+
+    public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
+        // converters.add(new PropertiesHttpMessageConverter());
+        // 指定顺序，这里为第一个
+        converters.add(0, new PropertiesHttpMessageConverter());
+    }
+
+}

47.Spring-Boot-Content-Negotiation/src/main/java/com/example/demo/controller/TestController.java

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+package com.example.demo.controller;
+
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.ResponseBody;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.Properties;
+
+/**
+ * @author MrBird
+ */
+// @RestController
+@Controller
+public class TestController {
+
+    @GetMapping(value = "test", consumes = "text/properties")
+    @ResponseBody
+    public Properties getUser(@RequestBody Properties properties) {
+        return properties;
+    }
+
+    @GetMapping(value = "test1", consumes = "text/properties")
+    // @ResponseBody
+    public Properties getUser1(Properties properties) {
+        return properties;
+    }
+}

47.Spring-Boot-Content-Negotiation/src/main/java/com/example/demo/converter/PropertiesHttpMessageConverter.java

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+package com.example.demo.converter;
+
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpInputMessage;
+import org.springframework.http.HttpOutputMessage;
+import org.springframework.http.MediaType;
+import org.springframework.http.converter.AbstractGenericHttpMessageConverter;
+import org.springframework.http.converter.HttpMessageNotReadableException;
+import org.springframework.http.converter.HttpMessageNotWritableException;
+
+import java.io.*;
+import java.lang.reflect.Type;
+import java.nio.charset.Charset;
+import java.util.Properties;
+
+/**
+ * @author MrBird
+ */
+public class PropertiesHttpMessageConverter extends AbstractGenericHttpMessageConverter<Properties> {
+
+    public PropertiesHttpMessageConverter() {
+        super(new MediaType("text", "properties"));
+    }
+
+    @Override
+    protected void writeInternal(Properties properties, Type type, HttpOutputMessage outputMessage) throws IOException, HttpMessageNotWritableException {
+        // 获取请求头
+        HttpHeaders headers = outputMessage.getHeaders();
+        // 获取 content-type
+        MediaType contentType = headers.getContentType();
+        // 获取编码
+        Charset charset = null;
+        if (contentType != null) {
+            charset = contentType.getCharset();
+        }
+
+        charset = charset == null ? Charset.forName("UTF-8") : charset;
+
+        // 获取请求体
+        OutputStream body = outputMessage.getBody();
+        OutputStreamWriter outputStreamWriter = new OutputStreamWriter(body, charset);
+
+        properties.store(outputStreamWriter, "Serialized by PropertiesHttpMessageConverter#writeInternal");
+    }
+
+    @Override
+    protected Properties readInternal(Class<? extends Properties> clazz, HttpInputMessage inputMessage) throws IOException, HttpMessageNotReadableException {
+        Properties properties = new Properties();
+        // 获取请求头
+        HttpHeaders headers = inputMessage.getHeaders();
+        // 获取 content-type
+        MediaType contentType = headers.getContentType();
+        // 获取编码
+        Charset charset = null;
+        if (contentType != null) {
+            charset = contentType.getCharset();
+        }
+
+        charset = charset == null ? Charset.forName("UTF-8") : charset;
+
+        // 获取请求体
+        InputStream body = inputMessage.getBody();
+        InputStreamReader inputStreamReader = new InputStreamReader(body, charset);
+
+        properties.load(inputStreamReader);
+        return properties;
+    }
+
+    @Override
+    public Properties read(Type type, Class<?> contextClass, HttpInputMessage inputMessage) throws IOException, HttpMessageNotReadableException {
+        return readInternal(null, inputMessage);
+    }
+}

47.Spring-Boot-Content-Negotiation/src/main/java/com/example/demo/handler/PropertiesHandlerMethodReturnValueHandler.java

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+package com.example.demo.handler;
+
+import org.springframework.core.MethodParameter;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
+import org.springframework.http.server.ServletServerHttpResponse;
+import org.springframework.web.context.request.NativeWebRequest;
+import org.springframework.web.context.request.ServletWebRequest;
+import org.springframework.web.method.support.HandlerMethodReturnValueHandler;
+import org.springframework.web.method.support.ModelAndViewContainer;
+
+import javax.servlet.http.HttpServletResponse;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import java.nio.charset.Charset;
+import java.util.Properties;
+
+/**
+ * @author MrBird
+ */
+public class PropertiesHandlerMethodReturnValueHandler implements HandlerMethodReturnValueHandler {
+
+    @Override
+    public boolean supportsReturnType(MethodParameter returnType) {
+        return Properties.class.equals(returnType.getMethod().getReturnType());
+    }
+
+    @Override
+    public void handleReturnValue(Object returnValue, MethodParameter returnType, ModelAndViewContainer mavContainer, NativeWebRequest webRequest) throws Exception {
+        Properties properties = (Properties) returnValue;
+
+        ServletWebRequest servletWebRequest = (ServletWebRequest) webRequest;
+
+        HttpServletResponse response = servletWebRequest.getResponse();
+        ServletServerHttpResponse servletServerHttpResponse = new ServletServerHttpResponse(response);
+
+        // 获取请求头
+        HttpHeaders headers = servletServerHttpResponse.getHeaders();
+
+        MediaType contentType = headers.getContentType();
+        // 获取编码
+        Charset charset = null;
+        if (contentType != null) {
+            charset = contentType.getCharset();
+        }
+
+        charset = charset == null ? Charset.forName("UTF-8") : charset;
+
+        // 获取请求体
+        OutputStream body = servletServerHttpResponse.getBody();
+        OutputStreamWriter outputStreamWriter = new OutputStreamWriter(body, charset);
+
+        properties.store(outputStreamWriter, "Serialized by PropertiesHandlerMethodReturnValueHandler#handleReturnValue");
+
+        // 告诉 Spring MVC 请求已经处理完毕
+        mavContainer.setRequestHandled(true);
+    }
+}

47.Spring-Boot-Content-Negotiation/src/main/java/com/example/demo/resolver/PropertiesHandlerMethodArgumentResolver.java

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+package com.example.demo.resolver;
+
+import org.springframework.core.MethodParameter;
+import org.springframework.http.MediaType;
+import org.springframework.web.bind.support.WebDataBinderFactory;
+import org.springframework.web.context.request.NativeWebRequest;
+import org.springframework.web.context.request.ServletWebRequest;
+import org.springframework.web.method.support.HandlerMethodArgumentResolver;
+import org.springframework.web.method.support.ModelAndViewContainer;
+
+import javax.servlet.http.HttpServletRequest;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.nio.charset.Charset;
+import java.util.Properties;
+
+/**
+ * @author MrBird
+ */
+public class PropertiesHandlerMethodArgumentResolver implements HandlerMethodArgumentResolver {
+    @Override
+    public boolean supportsParameter(MethodParameter parameter) {
+        return Properties.class.equals(parameter.getParameterType());
+    }
+
+    @Override
+    public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer, NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception {
+        ServletWebRequest servletWebRequest = (ServletWebRequest) webRequest;
+        HttpServletRequest request = servletWebRequest.getRequest();
+        String contentType = request.getHeader("Content-Type");
+
+        MediaType mediaType = MediaType.parseMediaType(contentType);
+        // 获取编码
+        Charset charset = mediaType.getCharset() == null ? Charset.forName("UTF-8") : mediaType.getCharset();
+        // 获取输入流
+        InputStream inputStream = request.getInputStream();
+        InputStreamReader inputStreamReader = new InputStreamReader(inputStream, charset);
+
+        // 输入流转换为 Properties
+        Properties properties = new Properties();
+        properties.load(inputStreamReader);
+        return properties;
+    }
+}

47.Spring-Boot-Content-Negotiation/src/main/resources/application.properties

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+

47.Spring-Boot-Content-Negotiation/src/test/java/com/example/demo/DemoApplicationTests.java

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+package com.example.demo;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit4.SpringRunner;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest
+public class DemoApplicationTests {
+
+    @Test
+    public void contextLoads() {
+    }
+
+}