jquery中ajax的使用(java)详解编程语言

$(document).ready(function(){  
    //===============GET============================== 
    $("#username").blur(function(){  
        $.ajax({  
            type: "GET",      
            url: prjContextPath + "/zhuceAction!queryUserName.action?username=" + $("#username").val()+"&pwd="+$("#pwd").val(), 
            dataType: "json", 
            success: function(data) { 
                if (data.success) {  
                     $("#usernamemsg").html("<font color='green'>" + data.msg + "</font>"); 
                } else { 
                    $("#usernamemsg").html("<font color='red'>" + data.msg + "</font>"); 
                }   
            }, 
            error: function(jqXHR){      
               alert("发生错误：" + jqXHR.status);   
            }      
        }); 
    }); 
     
  //===============POST============================== 
    $("#username").blur(function(){  
        $.ajax({  
            type: "POST",      
            url: prjContextPath + "/zhuceAction!queryUserName.action", 
            data: { 
                username: $("#username").val(),  
                pwd: $("#pwd").val() 
            }, 
            dataType: "json", 
            success: function(data){ 
                if (data.success) {  
                     $("#usernamemsg").html("<font color='green'>" + data.msg + "</font>"); 
                } else { 
                     $("#usernamemsg").html("<font color='red'>" + data.msg + "</font>"); 
                }   
            }, 
            error: function(jqXHR){      
               alert("发生错误：" + jqXHR.status);   
            }     
        }); 
    }); 
});

public void queryUserName() throws IOException { 
 
        System.out.println("username=" + user.getUsername()); 
        System.out.println("pwd=" + user.getPwd()); 
        // 去数据库中验证 
        boolean flag = true; 
         
        //形成JSON串 
        String  html = ""; 
        if (flag) { 
            html = "{/"success/":1,/"msg/":/"用户名，可以使用！/"}"; 
        } else { 
            html = "{/"success/":0,/"msg/":/"用户名，不可以使用！/"}"; 
        } 
 
        // 调用BaseAction中的方法向输出流中写JSON串 
        responseWriterJSON(html); 
 
    }

package action; 
 
import java.io.IOException; 
import java.io.PrintWriter; 
 
import javax.servlet.http.HttpServletResponse; 
 
import org.apache.struts2.ServletActionContext; 
 
 
 
public class BaseAction { 
 
    public HttpServletResponse response; 
    /** 
     * 返回页面数据 
     * @param returnString 返回数据 
     * @throws IOException 异常 
     */ 
    public void responseWriterJSON(String returnString) throws IOException  { 
         
        response = ServletActionContext.getResponse(); 
        response.setContentType("application/json;charset=utf-8"); 
         
            response.getWriter().write(returnString); 
            response.flushBuffer(); 
            response.getWriter().close(); 
          
    } 
    /** 
     * 返回页面xml数据 
     * @param returnString 返回数据 
     * @throws IOException  异常 
     */ 
    public void responseWriterXML(String returnString) throws IOException  { 
         
        response = ServletActionContext.getResponse(); 
        response.setCharacterEncoding("utf-8"); 
        response.setContentType("text/xml"); 
        response.setHeader("Cache-Control", "no-cache"); 
         
            response.getWriter().write(returnString); 
            response.flushBuffer(); 
            response.getWriter().close(); 
         
    } 
    /** 
     * 返回页面数据 
     * @param returnString 
     * @throws IOException  异常 
     */ 
    public void printWriter(String returnString) throws IOException { 
         
        response = ServletActionContext.getResponse(); 
        response.setContentType("text/html;charset=utf-8"); 
         
            PrintWriter out = response.getWriter(); 
            out.println(returnString); 
            out.close(); 
         
    } 
     
}

//-----------对用户名进行查询start------------------------------------------- 
$(document).ready(function() { 
     
         
        query(); 
     
}); 
 
 
//-----------对用户名进行查询end------------------------------------------- 
//加载查询土地登记审批表（判断:add/update/search） 
function query() 
{   
    var username = "aa"; 
    var pwd = "bb"; 
     
    $.post(prjContextPath+"/updateAction!query.action", 
    {username:username,pwd:pwd},callBackQuerySuccess); 
} 
 
function callBackQuerySuccess(json) 
{    
     
    if(json.data != null || json.data !="") 
    { 
        //向页面赋值 
        /* 
         * 方法1 
         for(var i=0;i<json.data.length;i++) 
        {   var tbBody = ""; 
            var trColor=""; 
            alert("i="+i); 
            var editData=json.data[i]; 
             
            if (i % 2 == 0) { 
              trColor = "even"; 
            } 
            else { 
              trColor = "odd"; 
            } 
            tbBody += "<tr class='" + trColor + "'><td>" + editData.name + "</td>" + "<td>" + editData.age + "</td></tr>"; 
            $("#myTb").append(tbBody); 
 
        } 
        */ 
         
         
        //向页面赋值方法2 
         var typeData = json.data; 
          $.each(typeData, function(i, n) { 
            var tbBody = "" 
            var trColor; 
            if (i % 2 == 0) { 
              trColor = "even"; 
            } 
            else { 
              trColor = "odd"; 
            } 
            tbBody += "<tr class='" + trColor + "'><td>" + n.name + "</td>" + "<td>" + n.age + "</td>" + "<td>" + n.like[0] + "</td></tr>"; 
            $("#myTb").append(tbBody); 
          }); 
 
         
    } 
}

package action; 
 
 
 
import java.io.IOException; 
import java.util.ArrayList; 
import java.util.List; 
 
import bean.User; 
import bean.UserInfo; 
 
 
import com.alibaba.fastjson.JSON; 
import com.opensymphony.xwork2.ModelDriven; 
 
public class UpdateAction extends BaseAction implements ModelDriven<User> { 
 
    User user = new User(); 
 
    public User getModel() { 
        return user; 
    } 
 
    public void query() throws IOException { 
 
        System.out.println("username=" + user.getUsername()); 
        System.out.println("pwd=" + user.getPwd()); 
         
         
        UserInfo userinfo = new UserInfo(); 
        userinfo.setName("张三"); 
        userinfo.setAge(20); 
        userinfo.setBirthday("1990-10-09"); 
        String[] likes = new String[] { "篮球", "足球" }; 
        userinfo.setLike(likes); 
        userinfo.setHasgirlfirend(false); 
        userinfo.setCar(null); 
         
        UserInfo userinfo2 = new UserInfo(); 
        userinfo2.setName("李四"); 
        userinfo2.setAge(20); 
        userinfo2.setBirthday("1991-11-11"); 
        String[] likes1 = new String[] { "台球", "羽毛球" }; 
        userinfo2.setLike(likes1); 
        userinfo2.setHasgirlfirend(false); 
        userinfo2.setCar(null); 
        List<UserInfo> userJsonList = new ArrayList<UserInfo>(); 
        userJsonList.add(userinfo); 
        userJsonList.add(userinfo2); 
 
        String jsonArray = JSON.toJSONString(userJsonList); 
         
        StringBuffer responseString = new StringBuffer(); 
        responseString.append("{/"total/":") 
        .append(2) 
        .append(",/"data/":") 
        .append(jsonArray) 
        .append("}"); 
         
         
        System.out.println(responseString.toString()); 
 
        // 调用BaseAction中的方法向输出流中写JSON串 
        responseWriterJSON(responseString.toString()); 
       /** 
       { 
    "total": 2, 
    "data": [{ 
        "age": 20, 
        "birthday": "1990-10-09", 
        "hasgirlfirend": false, 
        "like": ["篮球", "足球"], 
        "name": "张三1" 
    }, { 
        "age": 20, 
        "birthday": "1990-10-09", 
        "hasgirlfirend": false, 
        "like": ["篮球", "足球"], 
        "name": "张三" 
    }] 
    } 
   */ 
        } 
 
}