java解决跨域访问。

直接使用第一种方法，需要自己构建参数。

参考 

http://blog.sina.com.cn/s/blog_6eec2bb50100z93z.html

http://www.cnblogs.com/fx2008/p/4024971.html

Ajax JSON页面上直接跨域访问会遇到诸多问题：无法正常访问以及无法正常获取返回值等

可通过Ajax方式呼叫后台程式，交由java.net去呼叫跨域地址，解决此问题

以下為部分程式：

import java.net.URL;
import java.net.URLConnection;

 

static String url = "http://api.xxx.xxx.com/xxx/xxx?xxx=xx&xxx=xxx";

public String sendShortMessage(String smsSrc, String mobileNo) {

String line = "";
  StringBuffer sb = new StringBuffer();
  
  try {
   
   URL u = new URL(url);
   URLConnection uc = u.openConnection();
   
   uc.setDoOutput(true);
   
   BufferedReader in = new BufferedReader(new InputStreamReader(uc.getInputStream()));
   
   while ((line = in.readLine()) != null) {
    
    sb.append(line);

    System.err.println("readLine: " + sb.toString());

    // 此处获得即为跨域访问的返回值，这次测试获取的是JSON格式的字串
   }
  
   in.close();
  }
  catch (Exception e) {
   
   e.printStackTrace();
  }
  
  return new String(sb);
 }

java 服务端解决ajax跨域问题

//过滤器方式 可以更改为拦截器方式
public class SimpleCORSFilter implements Filter {

    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
        HttpServletResponse response = (HttpServletResponse) res;
        response.setHeader("Access-Control-Allow-Origin", "*");
        response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE");
        response.setHeader("Access-Control-Max-Age", "3600");
        response.setHeader("Access-Control-Allow-Headers", "x-requested-with");
        chain.doFilter(req, res);
    }

    public void init(FilterConfig filterConfig) {}

    public void destroy() {}

}