java運行txt

㈠ 緙栧啓java 紼嬪簭 鎵撳紑TXT鏂囦歡

浣犵殑txt鏂囦歡鍚嶅瓧鍙00.txt錛屾斁鍦╟鐩樻牴鐩褰曘傚唴瀹瑰啓鎴愶細
a
b
c
d
e
鎴栬咃細abcde銆傛垜緇欎綘鍐欎簡涓錛岃繍琛屾垚鍔熶簡錛
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
public class findFile {
public String loadAFileToStringDE(String path) throws IOException {
ArrayList Arry = new ArrayList();
File f = new File(path);
BufferedReader br = null;
String ret = null;
System.out.println(f);
try {
br = new BufferedReader(new FileReader(f));
String line = null;

while ((line = br.readLine()) != null) {

Arry.add(line);

}

} finally {
if (br != null) {
try {
br.close();
} catch (Exception e) {
}
}
}
String temp = (String)Arry.get(Arry.size()-1);
System.out.println("鏈鍚庝竴涓瀛楁瘝錛"+temp.substring(temp.length()-1,temp.length()));
return (String)Arry.get(Arry.size()-1);

}

public static void main(String[] args) {
findFile files= new findFile();
try{
System.out.println("鏈鍚庝竴琛"+files.loadAFileToStringDE("c:/00.txt"));
}catch(IOException io){}

}

}

緇撴灉錛
c:\00.txt
鏈鍚庝竴涓瀛楁瘝錛歟
鏈鍚庝竴琛宔

㈡ java中如何調用txt里的數據

創建一個數據讀取流

下面是一個把圖片存到資料庫的例子，你可以參考一下：

public class FileUtil {
private static Log log = LogFactory.getLog(FileUtil.class);

//將文件對象轉換為二進制位元組數組
public static byte[] toByteArray(File photo) throws IOException {
//獲得文件對象的輸入流
FileInputStream fis = new FileInputStream(photo);
BufferedInputStream bis = new BufferedInputStream(fis);

//位元組數組的輸出流
ByteArrayOutputStream baos = new ByteArrayOutputStream();
int c = bis.read();
while (c != -1) {
baos.write(c);
c = bis.read();
}
bis.close();
byte[] rtn = baos.toByteArray();
baos.close();
return rtn;
}

/**
* 構建小樣圖片
* @param srcFile
* @return
*/
public static byte[] buildThumbnail(File srcFile) {
byte[] rtn = null;
try {
Image src = ImageIO.read(srcFile); // 構造Image對象
int oldWidth = src.getWidth(null); // 得到源圖寬
int oldHeight = src.getHeight(null);// 得到源圖高

log.debug("old width is " + oldWidth);
log.debug("old height is " + oldHeight);

float divWidth = 200f; // 限制寬度為200
int newWidth = 200; // 縮略圖寬,
int newHeight = 0; // 縮略圖高
float tmp;//縮略比例
if (oldWidth > newWidth) {
tmp = oldWidth / divWidth;
newWidth = Math.round(oldWidth / tmp);// 計算縮略圖高
newHeight = Math.round(oldHeight / tmp);// 計算縮略圖高
log.debug("tmp scale is " + tmp);
} else {
newWidth = oldWidth;
newHeight = oldHeight;
}

//繪制的圖片默認大小
int imageHeight = 100;
int imageWidth = 200;

log.debug("new width is " + newWidth);
log.debug("new height is " + newHeight);

BufferedImage bufferedImage = new BufferedImage(newWidth,
newHeight, BufferedImage.TYPE_INT_RGB);

Graphics2D graphics2D = (Graphics2D) bufferedImage.createGraphics();
graphics2D.setBackground(Color.WHITE);
graphics2D.clearRect(0, 0, imageWidth, imageHeight);

//繪制新的圖片對象
bufferedImage.getGraphics().drawImage(src,
//(imageWidth - oldWidth) / 2, (imageHeight - newHeight) / 2,
0,0,
newWidth, newHeight, null); // 繪制縮小後的圖

ByteArrayOutputStream baos = new ByteArrayOutputStream();
BufferedOutputStream bos = new BufferedOutputStream(baos);
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(bos);
encoder.encode(bufferedImage); // 進行JPEG編碼
rtn = baos.toByteArray();
bos.close();
baos.close();
} catch (Exception e) {
log.debug(e);
} finally {

}
return rtn;
}
}

㈢ java怎樣實現讀寫TXT文件

主要有用到java原生態的Io類，沒有第三個包。直接上代碼：

importjava.io.*;

publicclasswrite{
publicstaticvoidmain(String[]args){
write("E://123.txt","hello");
}

publicstaticvoidwrite(Stringpath,Stringcontent){
try{
Filef=newFile(path);

if(f.exists()){
System.out.println("文件存在");
}else{
System.out.println("文件不存在，正在創建...");
if(f.createNewFile()){
System.out.println("文件創建成功！");
}else{
System.out.println("文件創建失敗！");
}
}
BufferedWriteroutput=newBufferedWriter(newFileWriter(f));
output.write(content);
output.close();
}catch(Exceptione){
e.printStackTrace();
}
}
}

㈣ 如何在Java中打開TXT文件

importjava.io.File;
importjava.io.FileInputStream;
importjava.io.FileNotFoundException;
importjava.io.IOException;

publicclassReadText{

	publicstaticvoidmain(String[]args)
	{
		readTextContent();
	}

	()
	{

		try
		{
			Filefile=newFile("E://test.txt");
			FileInputStreamfis=newFileInputStream(file);
			Stringstr="";
			byte[]bytes=newbyte[1024];
			intlength=0;
			while((length=fis.read(bytes))!=-1)
			{
				str+=newString(bytes,0,length);
			}

			System.out.println(str);

		}catch(FileNotFoundExceptione)
		{
			e.printStackTrace();
		}catch(IOExceptione)
		{
			e.printStackTrace();
		}
	}
}

㈤ java如何讀取txt文件

讀取txt文件（一整個獲取）