微信开发---发送客服消息

首先根据微信文档上给定的数据结构创建一个消息类实体：

public class KFMessage {

private String touser;
private String msgtype;
private MsgInfo text;


public KFMessage(String touser, String msgtype, String content) {
    super();
    this.touser = touser;
    this.msgtype = msgtype;
    text = new MsgInfo(content);
}
public String getTouser() {
    return touser;
}
public void setTouser(String touser) {
    this.touser = touser;
}
public String getMsgtype() {
    return msgtype;
}
public void setMsgtype(String msgtype) {
    this.msgtype = msgtype;
}
public MsgInfo getText() {
    return text;
}
public void setText(MsgInfo text) {
    this.text = text;
}

class MsgInfo{
    String content;

    public MsgInfo(String content) {
        super();
        this.content = content;
    }
}

}

然后就是发送客服消息的方法了，这里遇到的问题就是在向微信服务器post消息实体的时候一直post失败，失败的原因是把OutputStream 对象进行了包装，write了字符串，导致一直报44002，empty post data 的错误，其实什么都不用做，直接调用OutputStream 的write（Bytes byte）方法，把json格式的消息对象getBytes(“utf-8”)一下就可以了,注意，utf-8一定不能省，否则中文会乱码：
public static void replyKFMsg(String toUser,String msg) {

    try {
        URL url = new URL("https://api.weixin.qq.com/cgi-bin/message/custom/send?access_token="+wxToken);
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        connection.setRequestMethod("POST");
        connection.setRequestProperty("Charset", "UTF-8");
        connection.setRequestProperty("contentType", "application/json");
        connection.setRequestProperty("connection", "keep-alive");
        connection.setDoOutput(true);   
        connection.setDoInput(true);
        connection.connect();
        OutputStream out = connection.getOutputStream();  
        KFMessage kfMsg = new KFMessage(toUser, "text", msg);
        Gson g = new Gson();
        out.write(g.toJson(kfMsg).getBytes());

connection.disconnect();
} catch (Exception e) {
e.printStackTrace();
}
}