HttpServletRequest获取body中的参数

要获取HTTP请求中的请求体（body）中的参数，可以使用HttpServletRequest对象的getInputStream()方法和BufferedReader对象的readLine()方法。以下是一个示例代码：

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import javax.servlet.http.HttpServletRequest;

public class RequestBodyReader {

    public static String read(HttpServletRequest request) throws IOException {
        StringBuilder stringBuilder = new StringBuilder();
        BufferedReader bufferedReader = null;
        try {
            bufferedReader = new BufferedReader(new InputStreamReader(request.getInputStream(), "UTF-8"));
            char[] charBuffer = new char[128];
            int bytesRead = -1;
            while ((bytesRead = bufferedReader.read(charBuffer)) != -1) {
                stringBuilder.append(charBuffer, 0, bytesRead);
            }
        } catch (IOException ex) {
            throw ex;
        } finally {
            if (bufferedReader != null) {
                try {
                    bufferedReader.close();
                } catch (IOException ex) {
                    throw ex;
                }
            }
        }
        return stringBuilder.toString();
    }
}

可以使用如下代码调用该方法：

String body = RequestBodyReader.read(request);

其中，request是HttpServletRequest对象。返回的body即为请求体中的参数。