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
}

如果使用流读取器，请确保在结束时关闭流

private String readStream(InputStream iStream) throws IOException {
    //build a Stream Reader, it can read char by char
    InputStreamReader iStreamReader = new InputStreamReader(iStream);
    //build a buffered Reader, so that i can read whole line at once
    BufferedReader bReader = new BufferedReader(iStreamReader);
    String line = null;
    StringBuilder builder = new StringBuilder();
    while((line = bReader.readLine()) != null) {  //Read till end
        builder.append(line);
        builder.append("\n"); // append new line to preserve lines
    }
    bReader.close();         //close all opened stuff
    iStreamReader.close();
    //iStream.close(); //EDIT: Let the creator of the stream close it!
                       // some readers may auto close the inner stream
    return builder.toString();
}

编辑：在JDK7+上，可以使用trywithresources构造。

/**
 * Reads the stream into a string
 * @param iStream the input stream
 * @return the string read from the stream
 * @throws IOException when an IO error occurs
 */
private String readStream(InputStream iStream) throws IOException {

    //Buffered reader allows us to read line by line
    try (BufferedReader bReader =
                 new BufferedReader(new InputStreamReader(iStream))){
        StringBuilder builder = new StringBuilder();
        String line;
        while((line = bReader.readLine()) != null) {  //Read till end
            builder.append(line);
            builder.append("\n"); // append new line to preserve lines
        }
        return builder.toString();
    }
}

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")));
}

JDK 7/8应答，关闭流并仍然抛出IOException：

StringBuilder build = new StringBuilder();
byte[] buf = new byte[1024];
int length;
try (InputStream is = getInputStream()) {
  while ((length = is.read(buf)) != -1) {
    build.append(new String(buf, 0, length));
  }
}

在Groovy中

inputStream.getText()

此代码段位于\sdk\samples\android-19\connection\NetworkConnect\NetworkConnectSample\src\main\java.com\example\android\NetworkConnect\MainActivity.java中，该代码段根据Apache许可证2.0版授权，由Google编写。

/** Reads an InputStream and converts it to a String.
 * @param stream InputStream containing HTML from targeted site.
 * @param len Length of string that this method returns.
 * @return String concatenated according to len parameter.
 * @throws java.io.IOException
 * @throws java.io.UnsupportedEncodingException
 */
private String readIt(InputStream stream, int len) throws IOException, UnsupportedEncodingException {
    Reader reader = null;
    reader = new InputStreamReader(stream, "UTF-8");
    char[] buffer = new char[len];
    reader.read(buffer);
    return new String(buffer);
}