Question

为什么使用HttpClient发送json总是返回400

Answer 1

正好我这两天工作涉及到 java后台 json的交互
此代码肯定可以用：
public static String httpCall(String url, String json) {
String content ="";
try {
HttpClient httpClient = new DefaultHttpClient();
HttpPost post = new HttpPost(url);
post.setHeader("Content-type", "application/json;charset=utf-8");
StringEntity postingString = new StringEntity(json,"UTF-8");
postingString.setContentEncoding("utf-8");
// json传递
post.setEntity(postingString);
HttpResponse response = httpClient.execute(post);
content = EntityUtils.toString(response.getEntity());
} catch (Exception e) {
e.printStackTrace();
}
return content;
}

另外，建议用工具测试一下，确认接口能通。