InputStream,String,File相互转化_JAVA_编程开发_程序员俱乐部

1. String --> InputStream
InputStream String2InputStream(String str){
?? ByteArrayInputStream stream = new ByteArrayInputStream(str.getBytes());
?? return stream;
}

2. InputStream --> String
String inputStream2String(InputStream is){
?? BufferedReader in = new BufferedReader(new InputStreamReader(is));
?? StringBuffer buffer = new StringBuffer();
?? String line = "";
?? while ((line = in.readLine()) != null){
???? buffer.append(line);
?? }
?? return buffer.toString();
}

今天从网上看到了另一种方法，特拿来分享

String all_content=null;
??????? try {
??????? all_content =new String();

???????? InputStream ins = 获取的输入流;

????????? ByteArrayOutputStream outputstream = new ByteArrayOutputStream();
??????? byte[] str_b = new byte[1024];
??????? int i = -1;
??????? while ((i=ins.read(str_b)) > 0) {
??????? ?? outputstream.write(str_b,0,i);
??????? }
??????? all_content = outputstream.toString();
?? } catch (Exception e) {

e.printStackTrace();
????? }

此两种方法上面一种更快，但是比较耗内存，后者速度慢，耗资源少

3、File --> InputStream
InputStream in = new InputStream(new FileInputStream(File));

4、InputStream --> File
public void inputstreamtofile(InputStream ins,File file){
OutputStream os = new FileOutputStream(file);
int bytesRead = 0;
byte[] buffer = new byte[8192];
while ((bytesRead = ins.read(buffer, 0, 8192)) != -1) {
os.write(buffer, 0, bytesRead);
}
os.close();
ins.close();
}