test HttpServletResponseWrapper

Author: netbuffer

README.md

@@ -4,4 +4,5 @@
 [gitee源](https://gitee.com/netbuffer/javaee-demo)
 
 * /TestServlet 测试javaee监听器
-* [cors-filter跨域设置](http://software.dzhuvinov.com/cors-filter-installation.html)
+* [cors-filter跨域设置](http://software.dzhuvinov.com/cors-filter-installation.html)
+* 通过filter修改http response `ModifyHttpResponseFilter`

pom.xml

@@ -10,8 +10,7 @@
     <packaging>war</packaging>
 
     <name>javaee-demo Maven Webapp</name>
-    <!-- FIXME change it to the project's website -->
-    <url>http://www.example.com</url>
+    <url>https://github.com/netbuffer/javaee-demo</url>
 
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
@@ -23,7 +22,7 @@
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
-            <version>4.11</version>
+            <version>4.13.2</version>
             <scope>test</scope>
         </dependency>
         <dependency>
@@ -59,6 +58,11 @@
             <artifactId>java-property-utils</artifactId>
             <version>1.14</version>
         </dependency>
+        <dependency>
+            <groupId>com.alibaba</groupId>
+            <artifactId>fastjson</artifactId>
+            <version>1.2.78</version>
+        </dependency>
     </dependencies>
 
     <build>

src/main/java/cn/netbuffer/filter/ModifyHttpResponseFilter.java

@@ -0,0 +1,37 @@
+package cn.netbuffer.filter;
+
+import cn.netbuffer.filter.wrapper.ModifyHttpResponseWrapper;
+import com.alibaba.fastjson.JSON;
+import com.alibaba.fastjson.JSONObject;
+
+import javax.servlet.*;
+import javax.servlet.annotation.WebFilter;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+
+@WebFilter(filterName = "ModifyHttpResponseFilter", urlPatterns = {"/json/*"})
+public class ModifyHttpResponseFilter implements Filter {
+
+    @Override
+    public void init(FilterConfig filterConfig) throws ServletException {
+    }
+
+    @Override
+    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
+        HttpServletResponse httpServletResponse = (HttpServletResponse) servletResponse;
+        ModifyHttpResponseWrapper modifyHttpResponseWrapper = new ModifyHttpResponseWrapper(httpServletResponse);
+        System.out.println("-----------------before ModifyHttpResponseFilter------------------");
+        filterChain.doFilter(servletRequest, modifyHttpResponseWrapper);
+        System.out.println("-----------------after ModifyHttpResponseFilter------------------");
+        JSONObject jsonObject = JSON.parseObject(modifyHttpResponseWrapper.getResult());
+        jsonObject.put("msg", "wrapper[" + jsonObject.getString("msg") + "]");
+        HttpServletResponse response = (HttpServletResponse) modifyHttpResponseWrapper.getResponse();
+        response.setContentType("application/json; charset=UTF-8");
+        response.getWriter().write(jsonObject.toJSONString());
+    }
+
+    @Override
+    public void destroy() {
+    }
+
+}

src/main/java/cn/netbuffer/filter/wrapper/ModifyHttpResponseWrapper.java

@@ -0,0 +1,39 @@
+package cn.netbuffer.filter.wrapper;
+
+import javax.servlet.http.HttpServletResponse;
+import javax.servlet.http.HttpServletResponseWrapper;
+import java.io.CharArrayWriter;
+import java.io.IOException;
+import java.io.PrintWriter;
+
+public class ModifyHttpResponseWrapper extends HttpServletResponseWrapper {
+
+    private PrintWriter cacheWriter;
+    private CharArrayWriter bufferWriter;
+
+    public ModifyHttpResponseWrapper(HttpServletResponse response) {
+        super(response);
+        bufferWriter = new CharArrayWriter();
+        cacheWriter = new PrintWriter(bufferWriter);
+    }
+
+    @Override
+    public PrintWriter getWriter() throws IOException {
+        return cacheWriter;
+    }
+
+    /**
+     * 获取原始的HTML页面内容。
+     *
+     * @return
+     */
+    public String getResult() {
+        return bufferWriter.toString();
+    }
+
+    @Override
+    public void setContentType(String type) {
+        super.setContentType(type);
+    }
+
+}

src/main/java/cn/netbuffer/servlet/JSONServlet.java

@@ -0,0 +1,23 @@
+package cn.netbuffer.servlet;
+
+import com.alibaba.fastjson.JSONObject;
+import javax.servlet.ServletException;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+
+@WebServlet(name = "jsonServlet", urlPatterns = {"/json"})
+public class JSONServlet extends HttpServlet {
+
+    @Override
+    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+        JSONObject data = new JSONObject();
+        data.put("success", true);
+        data.put("msg", "invoke success for " + this.getClass().getName());
+        System.out.println("get json=" + data);
+        response.getWriter().write(data.toString());
+    }
+
+}

src/main/java/cn/netbuffer/servlet/PostServletTest.java

@@ -1,7 +1,5 @@
 package cn.netbuffer.servlet;
 
-import cn.lcfms.utils.Vardump;
-
 import javax.servlet.ServletException;
 import javax.servlet.annotation.WebServlet;
 import javax.servlet.http.HttpServlet;