Java読み書きbyte[]クラス
3670 ワード
package tools;
import java.io.BufferedOutputStream;
import java.io.BufferedWriter;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;
public class FileHelper {
//
public byte[] readByte(String filePath) throws IOException {
File file = new File(filePath);
long fileSize = file.length();
if (fileSize > Integer.MAX_VALUE) {
System.out.println("file too big...");
return null;
}
FileInputStream fi = new FileInputStream(file);
byte[] buffer = new byte[(int) fileSize];
int offset = 0;
int numRead = 0;
while (offset < buffer.length
&& (numRead = fi.read(buffer, offset, buffer.length - offset)) >= 0) {
offset += numRead;
}
//
if (offset != buffer.length) {
throw new IOException("Could not completely read file "+ file.getName());
}
fi.close();
return buffer;
}
//
public byte[] readByte2(String filePath) throws IOException
{
FileInputStream in=new FileInputStream(filePath);
ByteArrayOutputStream out=new ByteArrayOutputStream(1024);
System.out.println("bytes available:"+in.available());
byte[] temp=new byte[1024];
int size=0;
while((size=in.read(temp))!=-1)
{
out.write(temp,0,size);
}
in.close();
byte[] bytes=out.toByteArray();
System.out.println("bytes size got is:"+bytes.length);
return bytes;
}
// byte
public void WriteByteToFile(String path, byte[] content) throws IOException {
FileOutputStream fos = new FileOutputStream(path);
fos.write(content);
fos.close();
}
/* 1:
* byte ( )
*
* */
public void AppendByteToFile(String path, byte[] content, boolean Appendable) throws IOException {
//
//FileOutputStream fos = new FileOutputStream(path);
// , FileOutPutStream , openFileOutput FileOutputStream fos=new FileOutputStream(_sdpath1,Appendable);
FileOutputStream fos=new FileOutputStream(path,Appendable);
fos.write(content);
fos.write("\r
".getBytes());
fos.close();
}
/**
* :
* byte ,
*/
public void AppendByteToFile(byte[] bfile, String filePath,String fileName) {
BufferedOutputStream bos = null;
File file = null;
try {
File dir = new File(filePath);
if(!dir.exists()&&dir.isDirectory()){//
dir.mkdirs();
}
file = new File(filePath+"\\"+fileName);
/* 2 , */
/*bos = new BufferedOutputStream(new FileOutputStream(file));
bos.write(bfile); */
/* 3 , */
bos = new BufferedOutputStream(new FileOutputStream(file, true));
bos.write(bfile);
bos.write("\r
".getBytes());
bos.flush();
} catch (Exception e) {
e.printStackTrace();
} finally {
if (bos != null) {
try {
bos.close();
} catch (IOException e1) {
e1.printStackTrace();
}
}
}
}
}