jquery中的ajax应用

jquery中的ajax应用

function checkname(obj){
var val = obj.value;
var url ="AjaxServlet.do";
var param={uname:'张三2',tA:23};  //传对象
var data= "data="+"123";              //传字符串
var data2 ="data="+"123"+"&data2="+"456";  //传多个参数
$.ajax({
url: url,   // 请求路径
type: "POST",  //提交方式
dataType:'text', //获取数据类型，还可以是json、xml
cache:false,    //是否缓存
async:false,    //是否异步   true（异步）或 false（同步）
data:param,      //传入的参数
beforeSend:function(){  //请求发送之前触发，
alert("我要出发啦。。。。");
},
success:function(data){  //请求成功后返回的数据
alert("jquery==="+data);
data = eval("(" + data +")" );  //对获取到的数据进行处理，通过eval（）转化成js数组
alert("eval==="+data);
alert(data.userA.name);
}

});

}

resp.setContentType("text/html"); //必须加上
PrintWriter out =  resp.getWriter();
out.write("传入的值，一般为字符串");
out.flush();
out.close();

//          String jsonStr="{'name':'张三','upw':'123','age':'23','sex':'女'}";
//              User user = new User("张三", "123", 12, "男");
//              String jsonStr="{\"uname\": \""+ user.getName()+"\",\"age\":\""+user.getAge()+"\"}";
//                  resp.setContentType("text/html");
//                  PrintWriter out =  resp.getWriter();
//                  out.write(jsonStr);
//                  out.flush();
//                  out.close();

public static String transToJsonStr(Object obj){

ObjectMapper mapper = new ObjectMapper();
//     mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL); //表示自动去掉值为null的
StringWriter sw = new StringWriter();
String strJson = null ;
try {
mapper.writeValue(sw, obj);
strJson = sw.toString();
} catch (JsonGenerationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (JsonMappingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return strJson ;
}

public static void outJsonStrAndColse(HttpServletResponse resp,String jsonStr){
resp.setCharacterEncoding("utf-8");
resp.setContentType("text/html");
PrintWriter out;
try {
out = resp.getWriter();
out.write(jsonStr);
out.flush();
out.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}

User userA = new User("张三a", "123", 12, "男");
User userB = new User("张三b", "123", 122, "女");
List list  = new  ArrayList<User>();
list.add(userA);
list.add(userB);

String jsonstr = JsonUtil.transToJsonStr(list);
JsonUtil.outJsonStrAndColse(resp, jsonstr);