http請求requestUtils

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

import javax.servlet.http.HttpServletRequest;

import org.apache.commons.lang.StringUtils;

/**
 * <p> 
 *  <h3>Web Request 工具類</h3>
 *  <span> 該類使用 abstaract 修飾，防止用戶創建對象。其方法一般為靜態，如添加非靜態方法，修改者需提供具體子類。<span>
 *     <pre></pre>
 * </p>*/
public abstract class RequestUtils {
    
    
    /**
     * <p> 解析客戶端的 ip 地址  </p>
     */
    public static String getIpAddr(HttpServletRequest request) {
        String ip = request.getHeader("x-forwarded-for");
        if (StringUtils.isBlank(ip) || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }

        if (StringUtils.isBlank(ip) || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }

        if (StringUtils.isBlank(ip) || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }

        return ip;
    }
    
    /**
     * <p>獲取 request body 中的內容</p>
     * <span>該方法會拋出 IOException ，需調用者處理或者拋到更上層</span>*/
    public static String getRequestBody(HttpServletRequest request) throws IOException {
        
        StringBuilder sb = new StringBuilder() ;
        BufferedReader br = new BufferedReader(new InputStreamReader(request.getInputStream()));
        String line;
        
        //避免程序異常退出不能關閉
        try {
            while((line = br.readLine()) != null) {
                sb.append(line);
            }
        }finally { 
            br.close();
        }
        
        return sb.toString();
    }

}