将输入流转换成字符串教程

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.IOException;
import java.nio.charset.StandardCharsets;

public class InputStreamToString {

    public static String convertUsingBufferedReader(InputStream inputStream) throws IOException {
        StringBuilder result = new StringBuilder();

        try (BufferedReader reader = new BufferedReader(
                new InputStreamReader(inputStream, StandardCharsets.UTF_8))) {

            String line;
            while ((line = reader.readLine()) != null) {
                result.append(line).append("\n");
            }
        }

        // 去除最后多余的空行
        if (result.length() > 0) {
            result.setLength(result.length() - 1);
        }

        return result.toString();
    }

    // 逐行读取，保留行结构
    public static String convertWithLineBreaks(InputStream inputStream) throws IOException {
        StringBuilder result = new StringBuilder();

        try (BufferedReader reader = new BufferedReader(
                new InputStreamReader(inputStream, StandardCharsets.UTF_8))) {

            String line;
            boolean firstLine = true;
            while ((line = reader.readLine()) != null) {
                if (!firstLine) {
                    result.append(System.lineSeparator());
                }
                result.append(line);
                firstLine = false;
            }
        }

        return result.toString();
    }
}