http 请求时，通过反射拼接对象参数工具

package org.te;

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.text.SimpleDateFormat;
import java.util.Date;

public class GetParamter {

	public static void main(String[] args) throws Exception {

		User user = new User();
		user.setId(1);
		user.setName("name");

		String param = GetParamter.getPara(user);
		System.out.println(param);

	}

	public static String getPara(Gen<?> gen) throws Exception {

		Class<?> clz = gen.getGenType().getClass();

		StringBuffer result = new StringBuffer(512);
		Field[] field = clz.getDeclaredFields();

		result.append("?=");
		for (Field f : field) {
			Object o = getMethodValue(clz, gen.getGenType(), f.getName());
			if (o != null && !"".equals(o.toString())) {
				result.append(o + "&");
			}

		}
		result.delete(result.length() - 1, result.length());
		return result.toString();
	}

	/**
	 * 根据字段获取值
	 * 
	 * @param clz
	 * @param o
	 * @param field
	 * @return
	 */
	@SuppressWarnings("rawtypes")
	public static Object getMethodValue(Class clz, Object o, String field)
			throws NoSuchMethodException, SecurityException,
			IllegalAccessException, IllegalArgumentException,
			InvocationTargetException {

		Character charss = field.charAt(0);
		field = field.replaceFirst(charss.toString(),
				Character.toUpperCase(charss) + "");

		// 获取值
		@SuppressWarnings("unchecked")
		Method getMethod = clz.getDeclaredMethod("get" + field, new Class[] {});

		Object value = getMethod.invoke(o, new Object[] {});

		return value;
	}

	public static String converType(Object value, String dateFormat) {

		String rResult = "";

		// if (value instanceof Integer)
		// {
		// int result = (Integer) value;
		// return result;
		//
		// } else if (value instanceof Float)
		// {
		// float result = (Float) value;
		// return result;
		//
		// } else if (value instanceof Double)
		// {
		// double result = (Double) value;
		// return result;
		//
		// } else if (value instanceof Long)
		// {
		// long result = (Long) value;
		// return result;
		// }
		// if (value instanceof Boolean)
		// {
		// boolean result = (Boolean) value;
		// return result;
		//
		// } else
		if (value instanceof Date) {
			Date date = (Date) value;
			if ("".equals(dateFormat) || null == dateFormat) {
				dateFormat = "yyyy-MM-dd";

			}
			// IllegalArgumentException

			SimpleDateFormat sdf = new SimpleDateFormat(dateFormat);
			rResult = sdf.format(date);

		} else if (value instanceof byte[]) {
			//
		} else {

			return value + "";
		}
		return rResult;
	}

}

package org.te;

public interface Gen<T> {

	T getGenType();

}

package org.te;

public class User implements Gen<User> {
	private Integer id;
	private String name;

	public Integer getId() {
		return id;
	}

	public void setId(Integer id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	@Override
	public User getGenType() {
		return this;
	}

	@Override
	public String toString() {
		return "User [id=" + id + ", name=" + name + "]";
	}

}

package org.te;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLConnection;
import java.util.List;
import java.util.Map;

public class HttpRequest {
    /**
     * 向指定URL发送GET方法的请求
     * 
     * @param url
     *            发送请求的URL
     * @param param
     *            请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
     * @return URL 所代表远程资源的响应结果
     */
    public static String sendGet(String url, String param) {
        String result = "";
        BufferedReader in = null;
        try {
            String urlNameString = url + "?" + param;
            URL realUrl = new URL(urlNameString);
            // 打开和URL之间的连接
            URLConnection connection = realUrl.openConnection();
            // 设置通用的请求属性
            connection.setRequestProperty("accept", "*/*");
            connection.setRequestProperty("connection", "Keep-Alive");
            connection.setRequestProperty("user-agent",
                    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            // 建立实际的连接
            connection.connect();
            // 获取所有响应头字段
            Map<String, List<String>> map = connection.getHeaderFields();
            // 遍历所有的响应头字段
            for (String key : map.keySet()) {
                System.out.println(key + "--->" + map.get(key));
            }
            // 定义 BufferedReader输入流来读取URL的响应
            in = new BufferedReader(new InputStreamReader(
                    connection.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            System.out.println("发送GET请求出现异常！" + e);
            e.printStackTrace();
        }
        // 使用finally块来关闭输入流
        finally {
            try {
                if (in != null) {
                    in.close();
                }
            } catch (Exception e2) {
                e2.printStackTrace();
            }
        }
        return result;
    }

    /**
     * 向指定 URL 发送POST方法的请求
     * 
     * @param url
     *            发送请求的 URL
     * @param param
     *            请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
     * @return 所代表远程资源的响应结果
     */
    public static String sendPost(String url, String param) {
        PrintWriter out = null;
        BufferedReader in = null;
        String result = "";
        try {
            URL realUrl = new URL(url);
            // 打开和URL之间的连接
            URLConnection conn = realUrl.openConnection();
            // 设置通用的请求属性
            conn.setRequestProperty("Referer", "http://www.baidu.com");
            conn.setRequestProperty("accept", "*/*");
            conn.setRequestProperty("connection", "Keep-Alive");
            conn.setRequestProperty("user-agent",
                    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            // 发送POST请求必须设置如下两行
            conn.setDoOutput(true);
            conn.setDoInput(true);
            // 获取URLConnection对象对应的输出流
            out = new PrintWriter(conn.getOutputStream());
            // 发送请求参数
            out.print(param);
            // flush输出流的缓冲
            out.flush();
            // 定义BufferedReader输入流来读取URL的响应
            in = new BufferedReader(
                    new InputStreamReader(conn.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            System.out.println("发送 POST 请求出现异常！"+e);
            e.printStackTrace();
        }
        //使用finally块来关闭输出流、输入流
        finally{
            try{
                if(out!=null){
                    out.close();
                }
                if(in!=null){
                    in.close();
                }
            }
            catch(IOException ex){
                ex.printStackTrace();
            }
        }
        return result;
    }    
    
    public static void main(String[] args) {
        //发送 GET 请求
//        String s=HttpRequest.sendGet("http://192.168.20.249:8888/api/User/Login", "LoginName=en&LoginPwd=en");
//        System.out.println(s);
        
        //发送 POST 请求
        String sr=HttpRequest.sendPost("http://192.168.20.249:8888/api/User/Login", "LoginName=en&LoginPwd=en");
        System.out.println(sr);
    }
}