throws ServletException, IOException {
doGet(request, response);
}
}
别忘了纯Serlvet部属要在你的web.xml做配置。我的Serlvet的完整路进地址是:http://localhost:8080/JqueryStudy/chainSelect ,两句System.out.println()输出ajax传递过来的参数name和time。response.setCharacterEncoding(“UTF-8”)的作用是告诉浏览器字符串为utf-8的编码，防止中文乱码问题。response.setContentType(“application/json; charset=utf-8”)将返回的字符串以json格式形式返回。out对象是输出流，如果返回的是数组，格式应该如下：[“test1”, “test2”, “test3”]，如果是json类，则格式如下：{“name”:”fly”,”type”:”虫子”}。
上诉案例返回的是json对象,后台控制台输出:
name = John
time = 2pm
前端浏览器的控制台输出:
name : fly
type : 虫子
Servlet返回数组的案例如下：
代码清单1.6:demo.java
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;public class ChainSelect extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("name = " + request.getParameter("name"));
System.out.println("time = " + request.getParameter("time"));
response.setCharacterEncoding("UTF-8");
response.setContentType("application/json; charset=utf-8");
String jsonStr = "["test1", "test2", "test3"]";
PrintWriter out = null;
try {
out = response.getWriter();
out.write(jsonStr);
} catch (IOException e) {
e.printStackTrace();
} finally {
if (out != null) {
out.close();
}
}
}
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
前端jQuery代码:
$(document).ready(function(){
//发起ajax请求
$.post("../chainSelect", {name: "John", time: "2pm"}, function(data){
for(var i = 0; i < data.length; i++) {
console.log((i+1) + " : " + data[i]);
}
}, "json");
});后台之需要给jsonStr赋值为数组格式而已，而前端jQuery代码由于接收到的字符串数组，所以这里需要用遍历数组的形式来遍历。
本案例的Servlet代码清单：
代码清单1.7:ChainSelect.java
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
