标签：des style java 使用 os io 文件 for
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.io.RandomAccessFile;
import java.io.Reader;
import java.util.ArrayList;
import java.util.List;
/**
* java文件处理工具类
*
* @author lay at 2014年8月8日11:30:38
*
* @version 1.0
*/
public class FileUtil {
/**
* 复制文件
*
* @param srcPath
* 源文件
* @param desPath
* 目标文件
* @return boolean 是否复制成功
*/
public static boolean copyFile(String srcPath, String desPath) {
FileInputStream is = null;
OutputStream os = null;
BufferedInputStream bufInput = null;
BufferedOutputStream bufOnput = null;
File file = new File(desPath);
if (!file.getParentFile().exists()) {
file.getParentFile().mkdirs();
}
if (file.exists()) {
file = null;
return false;
}
if (!new File(srcPath).exists()) {
return false;
}
try {
is = new FileInputStream(srcPath);
os = new FileOutputStream(desPath);
bufInput = new BufferedInputStream(is);
bufOnput = new BufferedOutputStream(os);
int read = bufInput.read();
while (read != -1) {
bufOnput.write(read);
read = bufInput.read();
}
bufOnput.flush();
return true;
} catch (IOException e) {
return false;
} finally {
try {
if (bufInput != null) {
bufInput.close();
bufInput = null;
}
} catch (Exception e) {
}
try {
if (bufOnput != null) {
bufOnput.close();
bufOnput = null;
}
} catch (Exception e) {
}
try {
if (os != null) {
os.close();
os.close();
}
} catch (Exception e) {
}
try {
if (is != null) {
is.close();
is.close();
}
} catch (Exception e) {
}
}
}
/**
* 以对象流将对象写入文件
*
* @param filePath
* @param obj
*/
public static void writeObject(String filePath, Object obj) {
OutputStream os = null;
ObjectOutputStream oos = null;
File file = new File(filePath);
if (!file.getParentFile().exists()) {
file.getParentFile().mkdirs();
}
try {
os = new FileOutputStream(filePath);
oos = new ObjectOutputStream(os);
oos.writeObject(obj);
oos.flush();
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (oos != null) {
oos.close();
oos = null;
}
} catch (Exception e) {
e.printStackTrace();
}
try {
if (os != null) {
os.close();
os = null;
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
/**
* 以对象流从文件中读取对象
*
* @param filePath
* @return
*/
public static Object readObject(String filePath) {
Object obj = null;
FileInputStream is = null;
ObjectInputStream ois = null;
try {
is = new FileInputStream(filePath);
ois = new ObjectInputStream(is);
obj = ois.readObject();
} catch (Exception e) {
} finally {
try {
if (ois != null) {
ois.close();
}
} catch (IOException e) {
}
try {
if (is != null) {
is.close();
}
} catch (IOException e) {
}
}
return obj;
}
/**
* 以字节为单位读取文件，常用于读二进制文件，如图片、声音、影像等文件。
*
* @param fileName
* 文件的名
* @return
*/
public static byte[] readFileByBytes(String fileName) {
InputStream in = null;
byte[] b = null;
try {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte[] tempbytes = new byte[1024];
int len = 0;
in = new FileInputStream(fileName);
while ((len = in.read(tempbytes)) != -1) {
baos.write(tempbytes, 0, len);
}
byte[] temp = baos.toByteArray();
System.arraycopy(temp, 0, b, 0, temp.length);
baos = null;
temp = null;
} catch (Exception e1) {
e1.printStackTrace();
} finally {
if (in != null) {
try {
in.close();
} catch (IOException e1) {
}
}
}
return b;
}
/**
* 以字符为单位读取文件，常用于读文本，数字等类型的文件
*
* @param fileName
* 文件名
* @return
*/
public static char[] readFileByChars(String fileName) {
File file = new File(fileName);
Reader reader = null;
char[] ch = null;
try {
reader = new InputStreamReader(new FileInputStream(file));
List<Character> list = new ArrayList<Character>();
int tempchar;
while ((tempchar = reader.read()) != -1) {
list.add((char) tempchar);
}
reader.close();
ch = new char[list.size()];
for (int i = 0; i < list.size(); i++) {
ch[i] = list.get(i);
}
} catch (Exception e) {
e.printStackTrace();
}
return ch;
}
/**
* 以行为单位读取文件，常用于读面向行的格式化文件
*
* @param fileName
* 文件名
* @return
*/
public static String[] readFileByLines(String fileName) {
File file = new File(fileName);
BufferedReader reader = null;
String[] strs = null;
try {
List<String> list = new ArrayList<String>();
reader = new BufferedReader(new FileReader(file));
String tempString = null;
while ((tempString = reader.readLine()) != null) {
list.add(tempString);
}
reader.close();
strs = new String[list.size()];
strs = list.toArray(strs);
list = null;
} catch (IOException e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e1) {
}
}
}
return strs;
}
/**
* 随机读取文件内容
*
* @param fileName
* 文件名
*/
public static void readFileByRandomAccess(String fileName) {
RandomAccessFile randomFile = null;
try {
// 打开一个随机访问文件流，按只读方式
randomFile = new RandomAccessFile(fileName, "r");
// 文件长度，字节数
long fileLength = randomFile.length();
// 读文件的起始位置
int beginIndex = (fileLength > 4) ? 4 : 0;
// 将读文件的开始位置移到beginIndex位置。
randomFile.seek(beginIndex);
byte[] bytes = new byte[10];
int byteread = 0;
// 一次读10个字节，如果文件内容不足10个字节，则读剩下的字节。
// 将一次读取的字节数赋给byteread
while ((byteread = randomFile.read(bytes)) != -1) {
System.out.write(bytes, 0, byteread);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
if (randomFile != null) {
try {
randomFile.close();
} catch (IOException e1) {
}
}
}
}
/**
* A方法追加文件：使用RandomAccessFile
*
* @param fileName
* 文件名
* @param content
* 追加的内容
*/
public static void appendMethodA(String fileName, String content) {
try {
// 打开一个随机访问文件流，按读写方式
RandomAccessFile randomFile = new RandomAccessFile(fileName, "rw");
// 文件长度，字节数
long fileLength = randomFile.length();
// 将写文件指针移到文件尾。
randomFile.seek(fileLength);
randomFile.writeBytes(content);
randomFile.close();
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* B方法追加文件：使用FileWriter
*
* @param fileName
* 文件名
* @param content
* 追加的内容
*/
public static void appendMethodB(String fileName, String content) {
try {
// 打开一个写文件器，构造函数中的第二个参数true表示以追加形式写文件
FileWriter writer = new FileWriter(fileName, true);
writer.write(content);
writer.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
标签：des style java 使用 os io 文件 for
原文地址：http://www.cnblogs.com/sm21312/p/3899463.html
