如果您有java.io.InputStream对象,应该如何处理该对象并生成String?
假设我有一个包含文本数据的InputStream,我想将其转换为String,例如,我可以将其写入日志文件。
获取InputStream并将其转换为字符串的最简单方法是什么?
public String convertStreamToString(InputStream is) {
// ???
}
如果您有java.io.InputStream对象,应该如何处理该对象并生成String?
假设我有一个包含文本数据的InputStream,我想将其转换为String,例如,我可以将其写入日志文件。
获取InputStream并将其转换为字符串的最简单方法是什么?
public String convertStreamToString(InputStream is) {
// ???
}
当前回答
一个很好的方法是使用Apache Commons IOUItils将InputStream复制到StringWriter中。。。类似于
StringWriter writer = new StringWriter();
IOUtils.copy(inputStream, writer, encoding);
String theString = writer.toString();
甚至
// NB: does not close inputStream, you'll have to use try-with-resources for that
String theString = IOUtils.toString(inputStream, encoding);
或者,如果不想混合流和写入器,可以使用ByteArrayOutputStream。
其他回答
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));
}
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();
}
}
Use:
InputStream in = /* Your InputStream */;
StringBuilder sb = new StringBuilder();
BufferedReader br = new BufferedReader(new InputStreamReader(in));
String read;
while ((read=br.readLine()) != null) {
//System.out.println(read);
sb.append(read);
}
br.close();
return sb.toString();
基于已接受的Apache Commons答案的第二部分,但在始终关闭流的情况下填补了一个小缺口:
String theString;
try {
theString = IOUtils.toString(inputStream, encoding);
} finally {
IOUtils.closeQuietly(inputStream);
}
String inputStreamToString(InputStream inputStream, Charset charset) throws IOException {
try (
final StringWriter writer = new StringWriter();
final InputStreamReader reader = new InputStreamReader(inputStream, charset)
) {
reader.transferTo(writer);
return writer.toString();
}
}
纯Java标准库解决方案-无库自Java 10以来-Reader#transferTo(Java.io.Writer)无环溶液无新行字符处理