struts2 中不用配置json等jar包来实现低耦合，低入侵式ajax访问返回数据
1.首先要准备一个JSONUtile工具类，来实现数据的JSON转换
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.main.manage.entity.TCatalog;
import org.main.manage.entity.TNews;
import org.main.manage.entity.TProduct;
import org.main.manage.entity.TProductAttrib;
import org.main.manage.entity.TProductDeal;
import org.main.manage.entity.TProductPicture;
import org.main.manage.entity.TSeo;
import org.main.manage.entity.TWholesale;
/**
* 将Java object装换为JSON字符串.
*
* @author wangqun
*/
public final class JsonUtil {
//是否是第一次执行判断
private static int mapCount = 0;
/**
* Convert a Java object to JSON string.
*/
public static String toJson(Object o) throws NoSuchMethodException,InvocationTargetException,IllegalAccessException{
if (o==null)
return "null";
if (o instanceof List)
return array2Json(((List) o).toArray());
if (o instanceof String)
return string2Json((String)o);
if (o instanceof Boolean)
return boolean2Json((Boolean)o);
if (o instanceof Number)
return number2Json((Number)o);
if (o instanceof Date)
return date2Json((Date)o);
if (o instanceof Map)
return map2Json((Map)o);
if (o instanceof Object[])
return array2Json((Object[])o);
if (o instanceof int[])
return intArray2Json((int[])o);
if (o instanceof boolean[])
return booleanArray2Json((boolean[])o);
if (o instanceof long[])
return longArray2Json((long[])o);
if (o instanceof float[])
return floatArray2Json((float[])o);
if (o instanceof double[])
return doubleArray2Json((double[])o);
if (o instanceof short[])
return shortArray2Json((short[])o);
if (o instanceof byte[])
return byteArray2Json((byte[])o);
return entity2Json(o);
}
static String array2Json(Object[] array) throws NoSuchMethodException,InvocationTargetException,IllegalAccessException{
if (array.length==0)
return "[]";
StringBuffer sb = new StringBuffer(array.length << 4);
sb.append('[');
for (int i = 0; i < array.length; i++) {
Object o = array[i];
sb.append(toJson(o));
sb.append(',');
}
sb.setCharAt(sb.length()-1, ']');
return sb.toString();
}
static String intArray2Json(int[] array) {
if (array.length==0)
return "[]";
StringBuffer sb = new StringBuffer(array.length << 4);
sb.append('[');
for (int i = 0; i < array.length; i++) {
int o = array[i];
sb.append(Integer.toString(o));
sb.append(',');
}
sb.setCharAt(sb.length()-1, ']');
return sb.toString();
}
static String longArray2Json(long[] array) {
if (array.length==0)
return "[]";
StringBuffer sb = new StringBuffer(array.length << 4);
sb.append('[');
for (int i = 0; i < array.length; i++) {
long o = array[i];
sb.append(Long.toString(o));
sb.append(',');
}
sb.setCharAt(sb.length()-1, ']');
return sb.toString();
}
static String booleanArray2Json(boolean[] array) {
if (array.length==0)
return "[]";
StringBuffer sb = new StringBuffer(array.length << 4);
sb.append('[');
for (int i = 0; i < array.length; i++) {
boolean o = array[i];
sb.append(Boolean.toString(o));
sb.append(',');
}
sb.setCharAt(sb.length()-1, ']');
return sb.toString();
}
static String floatArray2Json(float[] array) {
if (array.length==0)
return "[]";
StringBuffer sb = new StringBuffer(array.length << 4);
sb.append('[');
for (int i = 0; i < array.length; i++) {
float o = array[i];
sb.append(Float.toString(o));
sb.append(',');
}
sb.setCharAt(sb.length()-1, ']');
return sb.toString();
}
static String doubleArray2Json(double[] array) {
if (array.length==0)
return "[]";
StringBuffer sb = new StringBuffer(array.length << 4);
sb.append('[');
for (int i = 0; i < array.length; i++) {
double o = array[i];
sb.append(Double.toString(o));
sb.append(',');
}
sb.setCharAt(sb.length()-1, ']');
return sb.toString();
}
static String shortArray2Json(short[] array) {
if (array.length==0)
return "[]";
StringBuffer sb = new StringBuffer(array.length << 4);
sb.append('[');
for (int i = 0; i < array.length; i++) {
short o = array[i];
sb.append(Short.toString(o));
sb.append(',');
}
sb.setCharAt(sb.length()-1, ']');
return sb.toString();
}
static String byteArray2Json(byte[] array) {
if (array.length==0)
return "[]";
StringBuffer sb = new StringBuffer(array.length << 4);
sb.append('[');
for (int i = 0; i < array.length; i++) {
byte o = array[i];
sb.append(Byte.toString(o));
sb.append(',');
}
sb.setCharAt(sb.length()-1, ']');
return sb.toString();
}
static String map2Json(Map map) throws NoSuchMethodException,InvocationTargetException,IllegalAccessException{
if (map.isEmpty())
return "{}";
StringBuffer sb = new StringBuffer(map.size() << 4);
if(mapCount++ > 0){
sb.append('[');
}
sb.append('{');
Set keys = map.keySet();
Iterator iters = keys.iterator();
while(iters.hasNext()){
String key = (String)iters.next();
Object value = map.get(key);
sb.append('\"');
sb.append(key);
sb.append('\"');
sb.append(':');
sb.append(toJson(value));
sb.append(',');
}
sb.setCharAt(sb.length()-1, '}');
//第一次执行标记
if(--mapCount > 0){
sb.append(']');
}
return sb.toString();
}
static String boolean2Json(Boolean bool) {
return bool.toString();
}
static String number2Json(Number number) {
return number.toString();
}
static String date2Json(Date date) {
if (null == date)
return "null";
StringBuffer sb = new StringBuffer();
sb.append('"');
sb.append(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(date));
sb.append('"');
return sb.toString();
}
static String string2Json(String s) {
StringBuffer sb = new StringBuffer(s.length()+20);
sb.append('\"');
for (int i=0; i<s.length(); i++) {
char c = s.charAt(i);
switch (c) {
case '\"':
sb.append("\\\"");
break;
case '\\':
sb.append("\\\\");
break;
case '/':
sb.append("\\/");
break;
case '\b':
sb.append("\\b");
break;
case '\f':
sb.append("\\f");
break;
case '\n':
sb.append("\\n");
break;
case '\r':
sb.append("\\r");
break;
case '\t':
sb.append("\\t");
break;
default:
sb.append(c);
}
}
sb.append('\"');
return sb.toString();
}
static String entity2Json(Object o) throws NoSuchMethodException,InvocationTargetException,IllegalAccessException{
if (null == o)
return "null";
return toJson(getBeanMap(o));
}
public static Map getBeanMap(Object obj) throws NoSuchMethodException,InvocationTargetException,IllegalAccessException{
if(null == obj){
return null;
}
Map resMap = new HashMap();
Method[] methods = obj.getClass().getDeclaredMethods();
for (int i = 0; i < methods.length; i++) {
Method method = methods[i];
String methodName = method.getName();
if(methodName.startsWith("get")){
Object methodValue = obj.getClass().getDeclaredMethod(methodName, null).invoke(obj, null);
String attrName = methodName.substring(3,4).toLowerCase()+methodName.substring(4);
resMap.put(attrName, methodValue);
valiAttr(methodValue);
}
}
return resMap;
}
/**
* 判断属性是否为集合，如果为集合外部用"[]"包裹
* @param obj
*/
public static void valiAttr(Object o){
if (o instanceof Map)
return ;
if (o instanceof Object[])
return;
if (o instanceof int[])
return;
if (o instanceof boolean[])
return;
if (o instanceof long[])
return;
if (o instanceof float[])
return;
if (o instanceof double[])
return;
if (o instanceof short[])
return;
if (o instanceof byte[])
return;
//"[]"执行标记
--mapCount;
}
}
这个可以对List、Map、自定义实体类数据等直接拼接
2.struts2框架搭建好后，在BaseAction中构建变量、方法
protected String ajaxData;
public String getAjaxData() {
return ajaxData;
}
public void setAjaxData(String ajaxData) {
this.ajaxData = ajaxData;
}
3.在struts.xml配置文件中配置全局返回页面
<global-results>
<result name="ajax" >/ajax.jsp</result>
</global-results>
ajax.jsp页面代码：
<%@ page language="java" pageEncoding="UTF-8" import="org.main.common.util.*"%> <%@ taglib prefix="s" uri="/struts-tags"%> <s:property value="ajaxData" escape="false"/>
设置escape="false"；如果不设置此属性，返回的标点符号会变成转义字符，如：“双引号”会变成“"”
public String test_json() throws Exception{
//逻辑代码
ajaxData = 返回数据;
return SUCCESS;
}
4.页面中js代码：
<script type="text/javascript">
function testJSON(){
$.ajax({url:'test_json.action',
data:{time:Math.random()},
dataType: "json",
success:function(res){
alert(res);
$.each(res,function(i,n){
alert(i+":"+n["orderNo"]);
})
}
});
}
</script>