什么是跨域
JavaScript出于安全方面的考虑，不允许跨域调用其他页面的对象。但在安全限制的同时也给注入iframe或是ajax应用上带来了不少麻烦。首先什么是跨域，简单地理解就是因为JavaScript同源策略的限制， 域名下的js无法操作或是c.域名下的对象。
function refreshDict(){
$.ajax({
type: "POST",
async: false,
cache : false,
url: "${appPath}/admin/dict/refreshDict.do",
dataType: "text",
success: function(data){
if(data == "success"){
msg = msg +"管理端刷新<span style='color:green;'><b>成功</b></span>";
}else{
msg = msg +"管理端刷新<span style='color:red;'><b>失败</b></span>";
}
},
error : function() {
msg = msg +"管理端刷新<span style='color:red;'><b>异常</b></span>";
}
});
msg += "<br>";
<c:forEach items="${interface_addr_list}" var="v" >
alert('${dValue}');
</c:forEach>
$.ajax({
type: "get",
async: false,
cache : false,
dataType:"jsonp",/*加上datatype*/
url: "http://192.168.1.253:8080/mobile2/refreshDict.json?jsoncallback=callback"
});
}
//callback方法名是固定的
function callback(data) {
if(data.code == "success"){
msg = msg +"接口服务端刷新<span style='color:green;'><b>成功</b></span>";
}else{
msg = msg +"接口服务端刷新<span style='color:red;'><b>失败</b></span>";
}
layer.alert(msg);
msg = "";
}
后台接口服务要返回内容类似如下：
String callbackName = request.getParameter("jsoncallback");
return callbackName+"({\"code\":\"SUCCESS\"})";
不想用ajax跨域也可以用后台请求：
public class HttpRequestUtil {
/**
* 发送Http post请求
* @param reqUrl
* @param data
* @return
*/
public static String doHttpPost(String reqUrl, String data) {
byte[] xmlData = null;
if(data != null){
xmlData = data.getBytes();
}
InputStream instr = null;
//java.io.ByteArrayOutputStream out = null;
try {
URL url = new URL(reqUrl);
URLConnection urlCon = url.openConnection();
urlCon.setDoOutput(true);
urlCon.setDoInput(true);
urlCon.setUseCaches(false);
urlCon.setRequestProperty("content-Type", "application/json");
urlCon.setRequestProperty("charset", "utf-8");
//urlCon.setRequestProperty("Content-length", String.valueOf(xmlData.length));
DataOutputStream printout = new DataOutputStream(urlCon.getOutputStream());
if(xmlData != null){
printout.write(xmlData);
}
printout.flush();
printout.close();
instr = urlCon.getInputStream();
byte[] bis = IOUtils.toByteArray(instr);
String ResponseString = new String(bis, "UTF-8");
/*if ((ResponseString == null) || ("".equals(ResponseString.trim()))) {
BaseConstant.MY_LOG.info("返回空");
}*/
BaseConstant.MY_LOG.info("返回数据为:" + ResponseString);
return ResponseString;
} catch (Exception e) {
e.printStackTrace();
return "-1";
} finally {
try {
/*if(out != null){
out.close();
}*/
if(instr != null){
instr.close();
}
} catch (Exception ex) {
return "-1";
}
}
}
public static void main(String[] args) {
doHttpPost("http://192.168.1.254:8080/mobile2/refreshDict.json", null);
}
}
public static String doHttpPost(String reqUrl) {
InputStream instr = null;
String result = null;
try {
URL url = new URL(reqUrl);
URLConnection urlCon = url.openConnection();
//获取响应码
/*HttpURLConnection httpURLConnection = (HttpURLConnection) new URL(reqUrl).openConnection();
httpURLConnection.setRequestMethod("POST");
int status = httpURLConnection.getResponseCode();
httpURLConnection.disconnect();
BaseConstant.MY_LOG.debug(status);*/
urlCon.setDoOutput(true);
urlCon.setDoInput(true);
urlCon.setUseCaches(false);
urlCon.setRequestProperty("content-Type", "application/json");
urlCon.setRequestProperty("charset", "utf-8");
DataOutputStream printout = new DataOutputStream(urlCon.getOutputStream());
printout.flush();
printout.close();
instr = urlCon.getInputStream();
result = IOUtils.toString(instr, StandardCharsets.UTF_8);
/*byte[] bis = IOUtils.toByteArray(instr);
return result = new String(bis, "UTF-8");*/
return result;
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if(instr != null){
instr.close();
}
} catch (Exception ex) {
BaseConstant.MY_LOG.error("InputStream关闭异常" + ex);
}
}
return result;
}
