ava 常用流处理工具 StreamTool ，常见的InputStream 流转字符串, 转字节数组等等
**应用场景：
** 1. 文件上传
2. js / css / img 等文件读取输出。 转字符串输出 (js & css) , 转字节数组输出 (img .. swf etc...)
3. 抓取指定 URL 连接的资源。
例如读取 javaniu 首页的 HTML 源代码
4. 如你所见....
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream; /**
* <pre>
* Java 常用流处理工具
* </pre>
*
* @project baidamei
* @author cevencheng <[email protected]>
* @create 2012-11-29 下午5:17:32
*/
public class StreamTool { /**
* 将流另存为文件
*
* @param is
* @param outfile
*/
public void streamSaveAsFile(InputStream is, File outfile) {
FileOutputStream fos = null;
try {
File file = outfile;
fos = new FileOutputStream(file);
byte[] buffer = new byte[1024];
int len;
while((len = is.read(buffer)) > 0){
fos.write(buffer, 0, len);
} } catch (Exception e) {
e.printStackTrace();
throw new RuntimeException(e);
} finally {
try {
is.close();
fos.close();
} catch (Exception e2) {
e2.printStackTrace();
throw new RuntimeException(e2);
}
}
}
/**
* Read an input stream into a string
* @param in
* @return
* @throws IOException
*/
static public String streamToString(InputStream in) throws IOException {
StringBuffer out = new StringBuffer();
byte[] b = new byte[4096];
for (int n; (n = in.read(b)) != -1;) {
out.append(new String(b, 0, n));
}
return out.toString();
}
public static byte[] stream2Byte(InputStream is) throws IOException {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
int len = 0;
byte[] b = new byte[1024];
while ((len = is.read(b, 0, b.length)) != -1) {
baos.write(b, 0, len);
}
byte[] buffer = baos.toByteArray();
return buffer;
}
/**
* @方法功能 InputStream 转为 byte
* @param InputStream
* @return 字节数组
* @throws Exception
*/
public static byte[] inputStream2Byte(InputStream inStream)
throws Exception {
// ByteArrayOutputStream outSteam = new ByteArrayOutputStream();
// byte[] buffer = new byte[1024];
// int len = -1;
// while ((len = inStream.read(buffer)) != -1) {
// outSteam.write(buffer, 0, len);
// }
// outSteam.close();
// inStream.close();
// return outSteam.toByteArray();
int count = 0;
while (count == 0) {
count = inStream.available();
}
byte[] b = new byte[count];
inStream.read(b);
return b;
} /**
* @方法功能 byte 转为 InputStream
* @param 字节数组
* @return InputStream
* @throws Exception
*/
public static InputStream byte2InputStream(byte[] b) throws Exception {
InputStream is = new ByteArrayInputStream(b);
return is;
} /**
* @功能 短整型与字节的转换
* @param 短整型
* @return 两位的字节数组
*/
public static byte[] shortToByte(short number) {
int temp = number;
byte[] b = new byte[2];
for (int i = 0; i < b.length; i++) {
b[i] = new Integer(temp & 0xff).byteValue();// 将最低位保存在最低位
temp = temp >> 8; // 向右移8位
}
return b;
} /**
* @功能 字节的转换与短整型
* @param 两位的字节数组
* @return 短整型
*/
public static short byteToShort(byte[] b) {
short s = 0;
short s0 = (short) (b[0] & 0xff);// 最低位
short s1 = (short) (b[1] & 0xff);
s1 <<= 8;
s = (short) (s0 | s1);
return s;
} /**
* @方法功能 整型与字节数组的转换
* @param 整型
* @return 四位的字节数组
*/
public static byte[] intToByte(int i) {
byte[] bt = new byte[4];
bt[0] = (byte) (0xff & i);
bt[1] = (byte) ((0xff00 & i) >> 8);
bt[2] = (byte) ((0xff0000 & i) >> 16);
bt[3] = (byte) ((0xff000000 & i) >> 24);
return bt;
} /**
* @方法功能 字节数组和整型的转换
* @param 字节数组
* @return 整型
* @author
*/
public static int bytesToInt(byte[] bytes) {
int num = bytes[0] & 0xFF;
num |= ((bytes[1] << 8) & 0xFF00);
num |= ((bytes[2] << 16) & 0xFF0000);
num |= ((bytes[3] << 24) & 0xFF000000);
return num;
} /**
* @方法功能 字节数组和长整型的转换
* @param 字节数组
* @return 长整型
*/
public static byte[] longToByte(long number) {
long temp = number;
byte[] b = new byte[8];
for (int i = 0; i < b.length; i++) {
b[i] = new Long(temp & 0xff).byteValue();
// 将最低位保存在最低位
temp = temp >> 8;
// 向右移8位
}
return b;
} /**
* @方法功能 字节数组和长整型的转换
* @param 字节数组
* @return 长整型
*/
public static long byteToLong(byte[] b) {
long s = 0;
long s0 = b[0] & 0xff;// 最低位
long s1 = b[1] & 0xff;
long s2 = b[2] & 0xff;
long s3 = b[3] & 0xff;
long s4 = b[4] & 0xff;// 最低位
long s5 = b[5] & 0xff;
long s6 = b[6] & 0xff;
long s7 = b[7] & 0xff; // s0不变
s1 <<= 8;
s2 <<= 16;
s3 <<= 24;
s4 <<= 8 * 4;
s5 <<= 8 * 5;
s6 <<= 8 * 6;
s7 <<= 8 * 7;
s = s0 | s1 | s2 | s3 | s4 | s5 | s6 | s7;
return s;
}
}