InputStream  inputStream = null;
BufferedReader bufferedReader = null;
try {
    BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
    String stringBuilder = new StringBuilder();
    String content;
    while((content = bufferedReader.readLine()) != null){
        stringBuilder.append(content);
    }
    System.out.println("content of file::" + stringBuilder.toString());
}
catch (IOException e) {
            e.printStackTrace();
        }finally{           
            if(bufferedReader != null){
                try{
                    bufferedReader.close();
                }catch(IoException ex){
                   ex.printStackTrace();
            }

此代码适用于新的Java学习者：

private String textDataFromFile;

public String getFromFile(InputStream myInputStream) throws FileNotFoundException, IOException {

    BufferedReader bufferReader = new BufferedReader(new InputStreamReader(myInputStream));

    StringBuilder stringBuilder = new StringBuilder();

    String eachStringLine;

    while ((eachStringLine = bufferReader.readLine()) != null) {
        stringBuilder.append(eachStringLine).append("\n");
    }
    textDataFromFile = stringBuilder.toString();

    return textDataFromFile;
}

注意：这可能不是个好主意。此方法使用递归，因此将非常快地命中StackOverflowError：

public String read (InputStream is) {
    byte next = is.read();
    return next == -1 ? "" : next + read(is); // Recursive part: reads next byte recursively
}

Kotlin用户只需：

println(InputStreamReader(is).readText())

鉴于

readText()

是Kotlin标准库的内置扩展方法。

您可以使用Apache Commons。

在IOUItils中，您可以找到toString方法以及三个有用的实现。

public static String toString(InputStream input) throws IOException {
        return toString(input, Charset.defaultCharset());
}

public static String toString(InputStream input) throws IOException {
        return toString(input, Charset.defaultCharset());
}

public static String toString(InputStream input, String encoding)
            throws IOException {
        return toString(input, Charsets.toCharset(encoding));
}

这是我的基于Java 8的解决方案，它使用新的流API来收集InputStream中的所有行：

public static String toString(InputStream inputStream) {
    BufferedReader reader = new BufferedReader(
        new InputStreamReader(inputStream));
    return reader.lines().collect(Collectors.joining(
        System.getProperty("line.separator")));
}