[置顶]再学java基础(7)java IO実戦【待续...】
import java.io.*;
public class TestFileInputStream {
public static void main(String[] args) {
int b = 0;
FileInputStream in = null;
try {
in = new FileInputStream("d:\\share\\java\\io\\TestFileInputStream.java");
} catch (FileNotFoundException e) {
System.out.println(" ");
System.exit(-1);
}
try {
long num = 0;
while((b=in.read())!=-1){ // 。 。。
System.out.print((char)b);
num++;
}
in.close();
System.out.println();
System.out.println(" "+num+" ");
} catch (IOException e1) {
System.out.println(" "); System.exit(-1);
}
}
}
import java.io.*;
public class TestFileOutputStream {
public static void main(String[] args) {
int b = 0;
FileInputStream in = null;
FileOutputStream out = null;
try {
in = new FileInputStream("d:/share/java/HelloWorld.java"); // ,
out = new FileOutputStream("d:/share/java/io/HW.java"); // FIleOutputStream 。
while((b=in.read())!=-1){
out.write(b);
}
in.close();
out.close();
} catch (FileNotFoundException e2) {
System.out.println(" "); System.exit(-1);
} catch (IOException e1) {
System.out.println(" "); System.exit(-1);
}
System.out.println(" ");
}
}
import java.io.*;
public class TestBufferStream1 {
public static void main(String[] args) {
try {
FileInputStream fis =
new FileInputStream("d:\\share\\java\\HelloWorld.java"); //
BufferedInputStream bis =
new BufferedInputStream(fis);
int c = 0;
System.out.println(bis.read());
System.out.println(bis.read());
bis.mark(100); // 100, 100 。
for(int i=0;i<=10 && (c=bis.read())!=-1;i++){
System.out.print((char)c+" ");
}
System.out.println();
bis.reset(); // 100 。
for(int i=0;i<=10 && (c=bis.read())!=-1;i++){
System.out.print((char)c+" ");
}
bis.close();
} catch (IOException e) {e.printStackTrace();}
}
}
import java.io.*;
public class TestBufferStream2 {
public static void main(String[] args) {
try {
// new FileWriter("d:\\share\\java\\dat2.txt") //
BufferedWriter bw = new BufferedWriter(new FileWriter("d:\\share\\java\\dat2.txt"));
BufferedReader br = new BufferedReader(
new FileReader("d:\\share\\java\\dat2.txt")); // 。
String s = null;
for(int i=1;i<=100;i++){
s = String.valueOf(Math.random());
bw.write(s); // 。
bw.newLine();
}
bw.flush();
while((s=br.readLine())!=null){
System.out.println(s);
}
bw.close();
br.close();
} catch (IOException e) { e.printStackTrace();}
}
}
import java.io.*;
public class TestFileWriter {
public static void main(String[] args) {
FileWriter fw = null;
try {
fw = new FileWriter("d:\\bak\\unicode.dat"); // 。
for(int c=0;c<=50000;c++){
fw.write(c);
}
fw.close();
} catch (IOException e1) {
e1.printStackTrace();
System.out.println(" ");
System.exit(-1);
}
}
}
import java.io.*;
public class TestFileWriter2 {
public static void main(String[] args) throws Exception {
FileReader fr = new FileReader("d:/java/io/TestFileWriter2.java");
FileWriter fw = new FileWriter("d:/java/io/TestFileWriter2.bak");
int b;
while((b = fr.read()) != -1) {
fw.write(b);
}
fr.close();
fw.close();
}
}
import java.io.*;
public class TestFileReader {
public static void main(String[] args) {
FileReader fr = null;
int c = 0;
try {
fr = new FileReader("d:\\share\\java\\io\\TestFileReader.java"); // 。
int ln = 0;
while ((c = fr.read()) != -1) {
//char ch = (char) fr.read();
System.out.print((char)c);
//if (++ln >= 100) { System.out.println(); ln = 0;}
}
fr.close();
} catch (FileNotFoundException e) {
System.out.println(" ");
} catch (IOException e) {
System.out.println(" ");
}
}
}
import java.io.*;
public class TestDataStream {
public static void main(String[] args) {
ByteArrayOutputStream baos =
new ByteArrayOutputStream(); //
DataOutputStream dos =
new DataOutputStream(baos); // 。
try {
dos.writeDouble(Math.random());
dos.writeBoolean(true);
ByteArrayInputStream bais =
new ByteArrayInputStream(baos.toByteArray());
System.out.println(bais.available());
DataInputStream dis = new DataInputStream(bais);
System.out.println(dis.readDouble());
System.out.println(dis.readBoolean());
dos.close(); dis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
1、書き込みデータ:
/**
*
*
* @param path
*
* @param dataList
* TXT
* @throws IOException
*/
public void writeTXT(String path, List<String> dataList) throws IOException {
BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(
new FileOutputStream(path, true)));
for (String string : dataList) {
bw.write(string);
bw.newLine();
}
bw.flush();
bw.close();
bw = null;
}
2、ファイルのコピー
/**
*
*
* @param fromPath
*
* @param toPath
*
*/
public void copyFile(String fromPath, String toPath) {
BufferedInputStream bis = null;
BufferedOutputStream bos = null;
System.out.println("copyFile start--- :" + fromPath + ", :"
+ toPath);
try {
bis = new BufferedInputStream(new FileInputStream(fromPath));
bos = new BufferedOutputStream(new FileOutputStream(toPath));
byte b[] = new byte[1024 * 8];
int i;
while ((i = bis.read(b)) > -1) {
bos.write(b, 0, i);
}
bos.flush();
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (bis != null)
bis.close();
if (bos != null)
bos.close();
} catch (IOException e) {
e.printStackTrace();
bis = null;
bos = null;
}
}
}
3,読み込んだpropertiesパス
/**
*
* @param propertiesPath
* properties
* @param propertiesKey
* properties key
* @return properties value
* @throws IOException
*/
public String getPropertiesValue(String propertiesPath,
String propertiesKey) throws IOException {
String path = PropertiesUtil.loadProperties(propertiesPath)
.getProperty(propertiesKey);
//
File file;
file = new File(path);
if (!file.exists()) {
file.mkdirs();
}
file = null;
//
file = new File(path);
if (!file.exists()) {
file.mkdirs();
}
file = null;
return PropertiesUtil.loadProperties(propertiesPath).getProperty(
propertiesKey);
}