一定要注意：
传入的参数，应该是包含文件名的完整路径名，
不能把一个文件复制到【文件夹】中，因为【文件夹】本身是不能有输入输出流的，只能复制到一个【文件】中，否则会报异常。
以字节流读写的三种方式
public class Test {
private static final String FILE_PATH = "e:\\";
private static final String FILE_TYPE = ".exe";
private static final String FILE_FROM = FILE_PATH + 0 + FILE_TYPE;
private static final String COPY_FILE_1 = FILE_PATH + 1 + FILE_TYPE;
private static final String COPY_FILE_2 = FILE_PATH + 2 + FILE_TYPE;
private static final String COPY_FILE_3 = FILE_PATH + 3 + FILE_TYPE;
public static void main(String[] args) throws IOException {
copyByBufStream(FILE_FROM, COPY_FILE_1);
copyByBufArray(FILE_FROM, COPY_FILE_2);
copyByByte(FILE_FROM, COPY_FILE_3);
}
/**
* 利用缓冲输入流读取到一个缓冲容器后再写入。建议使用
*/
public static boolean copyByBufStream(String filePathFrom, String filePathTo) {
try {
BufferedInputStream bufis = new BufferedInputStream(new FileInputStream(filePathFrom));
BufferedOutputStream bufos = new BufferedOutputStream(new FileOutputStream(filePathTo));
int ch = 0;
while ((ch = bufis.read()) != -1) {
bufos.write(ch);
}
bufos.close();
bufis.close();
return true;
} catch (FileNotFoundException e) {
e.printStackTrace();
return false;
} catch (IOException e) {
e.printStackTrace();
return false;
}
}
/**
* 每次读取一个指定长度数组的字节。建议使用
*/
public static boolean copyByBufArray(String filePathFrom, String filePathTo) {
try {
FileInputStream fis = new FileInputStream(filePathFrom);
FileOutputStream fos = new FileOutputStream(filePathTo);
byte[] buf = new byte[1024];
int len = 0;
while ((len = fis.read(buf)) != -1) {
fos.write(buf, 0, len);
}
fos.close();
fis.close();
return true;
} catch (FileNotFoundException e) {
e.printStackTrace();
return false;
} catch (IOException e) {
e.printStackTrace();
return false;
}
}
/**
* 一次读取一个字节。千万不要用，速度超级慢！
*/
public static boolean copyByByte(String filePathFrom, String filePathTo) {
try {
FileInputStream fis = new FileInputStream(filePathFrom);
FileOutputStream fos = new FileOutputStream(filePathTo);
int ch = 0;
while ((ch = fis.read()) != -1) {
fos.write(ch);
}
fos.close();
fis.close();
return true;
} catch (FileNotFoundException e) {
e.printStackTrace();
return false;
} catch (IOException e) {
e.printStackTrace();
return false;
}
}
}
以字符流读写的三种方式
public class Test {
private static final String FILE_PATH = "e:\\";
private static final String FILE_TYPE = ".txt";
private static final String FILE_FROM = FILE_PATH + 0 + FILE_TYPE;
private static final String COPY_FILE_1 = FILE_PATH + 1 + FILE_TYPE;
private static final String COPY_FILE_2 = FILE_PATH + 2 + FILE_TYPE;
private static final String COPY_FILE_3 = FILE_PATH + 3 + FILE_TYPE;
public static void main(String[] args) throws IOException {
//注意，只能复制纯文本格式的文件，否则就会出现乱码
copyByBufLine(FILE_FROM, COPY_FILE_1);
copyByBufArray(FILE_FROM, COPY_FILE_2);
copyByChar(FILE_FROM, COPY_FILE_3);
}
/**
* 一次写入一行字符
*/
public static boolean copyByBufLine(String filePathFrom, String filePathTo) {
try {
BufferedReader bufr = new BufferedReader(new FileReader(filePathFrom));
BufferedWriter bufw = new BufferedWriter(new FileWriter(filePathTo));
String line = null;
//另外开辟一个缓冲区，存储读取的一行数据，返回包含该行内容的字符串，不包含换行符，如果已到达流末尾，则返回【 null】
while ((line = bufr.readLine()) != null) {
bufw.write(line);
bufw.newLine();// 写入一个行分隔符
bufw.flush();
}
bufr.close();
bufw.close();
return true;
} catch (FileNotFoundException e) {
e.printStackTrace();
return false;
} catch (IOException e) {
e.printStackTrace();
return false;
}
}
/**
* 一次写入指定个数的字符
*/
public static boolean copyByBufArray(String filePathFrom, String filePathTo) {
try {
BufferedReader bufr = new BufferedReader(new FileReader(filePathFrom));
BufferedWriter bufw = new BufferedWriter(new FileWriter(filePathTo));
char[] buf = new char[1024];
int len = 0;
while ((len = bufr.read(buf)) != -1) {
bufw.write(buf, 0, len);
bufw.flush();
len = 0;
}
bufr.close();
bufw.close();
return true;
} catch (FileNotFoundException e) {
e.printStackTrace();
return false;
} catch (IOException e) {
e.printStackTrace();
return false;
}
}
/**
* 一次写入一个字符
*/
public static boolean copyByChar(String filePathFrom, String filePathTo) {
try {
BufferedReader bufr = new BufferedReader(new FileReader(filePathFrom));
BufferedWriter bufw = new BufferedWriter(new FileWriter(filePathTo));
int ch = 0;
while ((ch = bufr.read()) != -1) {
bufw.write(ch);//写入单个字符
}
bufr.close();
bufw.close();
return true;
} catch (FileNotFoundException e) {
e.printStackTrace();
return false;
} catch (IOException e) {
e.printStackTrace();
return false;
}
}
}