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
你可以使用仙人掌:
String text = new TextOf(inputStream).asString();
UTF-8编码是默认编码。如果您需要另一个:
String text = new TextOf(inputStream, "UTF-16").asString();
其他回答
考虑到文件,首先应该获得java.io.Reader实例。然后可以将其读取并添加到StringBuilder中(如果我们不在多个线程中访问StringBuffer,我们就不需要StringBuffer了,StringBuilder速度更快)。这里的技巧是我们在块中工作,因此不需要其他缓冲流。块大小被参数化以用于运行时性能优化。
public static String slurp(final InputStream is, final int bufferSize) {
final char[] buffer = new char[bufferSize];
final StringBuilder out = new StringBuilder();
try (Reader in = new InputStreamReader(is, "UTF-8")) {
for (;;) {
int rsz = in.read(buffer, 0, buffer.length);
if (rsz < 0)
break;
out.append(buffer, 0, rsz);
}
}
catch (UnsupportedEncodingException ex) {
/* ... */
}
catch (IOException ex) {
/* ... */
}
return out.toString();
}
下面的代码对我有用。
URL url = MyClass.class.getResource("/" + configFileName);
BufferedInputStream bi = (BufferedInputStream) url.getContent();
byte[] buffer = new byte[bi.available() ];
int bytesRead = bi.read(buffer);
String out = new String(buffer);
请注意,根据Java文档,available()方法可能不适用于InputStream,但始终适用于BufferedInputStream。如果您不想使用available()方法,我们可以始终使用以下代码
URL url = MyClass.class.getResource("/" + configFileName);
BufferedInputStream bi = (BufferedInputStream) url.getContent();
File f = new File(url.getPath());
byte[] buffer = new byte[ (int) f.length()];
int bytesRead = bi.read(buffer);
String out = new String(buffer);
我不确定是否会有任何编码问题。如果代码有任何问题,请发表评论。
另一个,对于所有Spring用户:
import java.nio.charset.StandardCharsets;
import org.springframework.util.FileCopyUtils;
public String convertStreamToString(InputStream is) throws IOException {
return new String(FileCopyUtils.copyToByteArray(is), StandardCharsets.UTF_8);
}
org.springframework.util.StreamUtils中的实用程序方法与FileCopyUtils中类似,但它们在完成后会使流保持打开状态。
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();
}
}
我已经创建了这段代码,并且它有效。没有所需的外部插件。
有一个字符串到流和流到字符串的转换器:
import java.io.ByteArrayInputStream;
import java.io.InputStream;
public class STRINGTOSTREAM {
public static void main(String[] args)
{
String text = "Hello Bhola..!\nMy Name Is Kishan ";
InputStream strm = new ByteArrayInputStream(text.getBytes()); // Convert String to Stream
String data = streamTostring(strm);
System.out.println(data);
}
static String streamTostring(InputStream stream)
{
String data = "";
try
{
StringBuilder stringbuld = new StringBuilder();
int i;
while ((i=stream.read())!=-1)
{
stringbuld.append((char)i);
}
data = stringbuld.toString();
}
catch(Exception e)
{
data = "No data Streamed.";
}
return data;
}