将Set集合对象转换为JSon格式的对象字符串，返回给界面
需要导入的jar包：
编写：servlet:
package com.west.webcourse.servlet; import java.io.IOException; import java.io.PrintWriter; import java.util.HashMap; import java.util.HashSet; import java.util.Map; import java.util.Set; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import net.sf.json.JSONArray; public class JavaBeanToJOSNString extends HttpServlet { /** 第02步：重写doGet()方法,下一步：测试 */ @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html;charset=utf-8"); PrintWriter out = response.getWriter(); System.out.println("转换"); out.print("转换后的JSON字符串："); /** 向浏览器发送JSon格式的字符串 */ out.print(getSetToJsonString()); out.flush(); out.close(); } /** 第01步：创建JSon格式字符串转换方法:将Set集合转换成json类型字符串 */ public String getSetToJsonString() { Set set=new HashSet(); set.add(Boolean.TRUE); set.add(new Integer(1)); set.add(new String[]{"zhang3","li4","wang5"}); set.add("function(arrayIndex){return this.arrayType[arrayIndex];}"); JSONArray setToJsonArray=new JSONArray().fromObject(set); System.out .println("com.west.webcourse.servlet.JavaBeanToJOSNString.java::" + setToJsonArray); return setToJsonArray.toString(); } }
测试servlet：
package com.west.webcourse.servlet; /** * 第03步：测试 * 下一步：配置web.xml */ import org.junit.BeforeClass; import org.junit.Test; public class JavaBeanToJOSNStringTest { static JavaBeanToJOSNString js; @BeforeClass public static void setUpBeforeClass() throws Exception { js=new JavaBeanToJOSNString(); } @Test public void testToJsonString() { js.getSetToJsonString(); } }
配置web.xml:
<?xml version="1.0" encoding="UTF-8"?> <web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <display-name></display-name> <!-- 第04步：配置servlet,下一步：personinfo.jsp --> <servlet> <description>This</description> <display-name>This</display-name> <servlet-name>JavaBeanToJOSNString</servlet-name> <servlet-class>com.west.webcourse.servlet.JavaBeanToJOSNString</servlet-class> </servlet> <servlet-mapping> <servlet-name>JavaBeanToJOSNString</servlet-name> <url-pattern>/javaBeanToJOSNString</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>personinfo.jsp</welcome-file> </welcome-file-list> </web-app>
编写界面：personinfo.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>My JSP 'personinfo.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> </head> <body> <!-- 第05步：编写界面 --> 动态获得当前项目的ContextPath所对应的目录：${pageContext.request.contextPath} <br> <a href="javaBeanToJOSNString">向servlet发送请求</a> <br> </body> </html>