Category: JAVA
idea 编译时提示包不存在
2020-09-16编辑
试了很多方法无果,找到一个方法,无敌!
在项目目录下执行mvn idea:idea 命令
IDEA 2019.02.07注册码
N757JE0KCT-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-AE3x5sRpDellY4SmQVy2Pfc2IT7y1JjZFmDA5JtOv4K5gwVdJOLw5YGiOskZTuGu6JhOi50nnd0WaaNZIuVVVx3T5MlXrAuO3kb2qPtLtQ6/n3lp4fIv+6384D4ciEyRWijG7NA9exQx39Tjk7/xqaGk7ooKgq5yquIfIA+r4jlbW8j9gas1qy3uTGUuZQiPB4lv3P5OIpZzIoWXnFwWhy7s//mjOWRZdf/Du3RP518tMk74wizbTeDn84qxbM+giNAn+ovKQRMYHtLyxntBiP5ByzfAA9Baa5TUGW5wDiZrxFuvBAWTbLrRI0Kd7Nb/tB9n1V9uluB2WWIm7iMxDg==-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
EditPlus 5.0.733 Full Version License Key
Vovan
3AG46-JJ48E-CEACC-8E6EW-ECUAW
使用NIO进行快速的文件拷贝
- public static void fileCopy( File in, File out )
- throws IOException
- {
- FileChannel inChannel = new FileInputStream( in ).getChannel();
- FileChannel outChannel = new FileOutputStream( out ).getChannel();
- try
- {
- // inChannel.transferTo(0, inChannel.size(), outChannel); // original — apparently has trouble copying large files on Windows
- // magic number for Windows, 64Mb – 32Kb)
- int maxCount = (64 * 1024 * 1024) – (32 * 1024);
- long size = inChannel.size();
- long position = 0;
- while ( position < size )
- {
- position += inChannel.transferTo( position, maxCount, outChannel );
- }
- }
- finally
- {
- if ( inChannel != null )
- {
- inChannel.close();
- }
- if ( outChannel != null )
- {
- outChannel.close();
- }
- }
- }
列出文件和目录
- File dir = new File(“directoryName”);
- String[] children = dir.list();
- if (children == null) {
- // Either dir does not exist or is not a directory
- } else {
- for (int i=0; i < children.length; i++) {
- // Get filename of file or directory
- String filename = children[i];
- }
- }
- // It is also possible to filter the list of returned files.
- // This example does not return any files that start with `.’.
- FilenameFilter filter = new FilenameFilter() {
- public boolean accept(File dir, String name) {
- return !name.startsWith(“.”);
- }
- };
- children = dir.list(filter);
- // The list of files can also be retrieved as File objects
- File[] files = dir.listFiles();
- // This filter only returns directories
- FileFilter fileFilter = new FileFilter() {
- public boolean accept(File file) {
- return file.isDirectory();
- }
- };
- files = dir.listFiles(fileFilter);
创建ZIP和JAR文件 create zip jar
- import java.util.zip.*;
- import java.io.*;
- public class ZipIt {
- public static void main(String args[]) throws IOException {
- if (args.length < 2) {
- System.err.println(“usage: java ZipIt Zip.zip file1 file2 file3”);
- System.exit(-1);
- }
- File zipFile = new File(args[0]);
- if (zipFile.exists()) {
- System.err.println(“Zip file already exists, please try another”);
- System.exit(-2);
- }
- FileOutputStream fos = new FileOutputStream(zipFile);
- ZipOutputStream zos = new ZipOutputStream(fos);
- int bytesRead;
- byte[] buffer = new byte[1024];
- CRC32 crc = new CRC32();
- for (int i=1, n=args.length; i < n; i++) {
- String name = args[i];
- File file = new File(name);
- if (!file.exists()) {
- System.err.println(“Skipping: “ + name);
- continue;
- }
- BufferedInputStream bis = new BufferedInputStream(
- new FileInputStream(file));
- crc.reset();
- while ((bytesRead = bis.read(buffer)) != –1) {
- crc.update(buffer, 0, bytesRead);
- }
- bis.close();
- // Reset to beginning of input stream
- bis = new BufferedInputStream(
- new FileInputStream(file));
- ZipEntry entry = new ZipEntry(name);
- entry.setMethod(ZipEntry.STORED);
- entry.setCompressedSize(file.length());
- entry.setSize(file.length());
- entry.setCrc(crc.getValue());
- zos.putNextEntry(entry);
- while ((bytesRead = bis.read(buffer)) != –1) {
- zos.write(buffer, 0, bytesRead);
- }
- bis.close();
- }
- zos.close();
- }
- }
解析/读取XML 文件
- <?xml version=“1.0”?>
- <students>
- <student>
- <name>John</name>
- <grade>B</grade>
- <age>12</age>
- </student>
- <student>
- <name>Mary</name>
- <grade>A</grade>
- <age>11</age>
- </student>
- <student>
- <name>Simon</name>
- <grade>A</grade>
- <age>18</age>
- </student>
- </students>
- package net.viralpatel.java.xmlparser;
- import java.io.File;
- import javax.xml.parsers.DocumentBuilder;
- import javax.xml.parsers.DocumentBuilderFactory;
- import org.w3c.dom.Document;
- import org.w3c.dom.Element;
- import org.w3c.dom.Node;
- import org.w3c.dom.NodeList;
- public class XMLParser {
- public void getAllUserNames(String fileName) {
- try {
- DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
- DocumentBuilder db = dbf.newDocumentBuilder();
- File file = new File(fileName);
- if (file.exists()) {
- Document doc = db.parse(file);
- Element docEle = doc.getDocumentElement();
- // Print root element of the document
- System.out.println(“Root element of the document: “
- + docEle.getNodeName());
- NodeList studentList = docEle.getElementsByTagName(“student”);
- // Print total student elements in document
- System.out
- .println(“Total students: “ + studentList.getLength());
- if (studentList != null && studentList.getLength() > 0) {
- for (int i = 0; i < studentList.getLength(); i++) {
- Node node = studentList.item(i);
- if (node.getNodeType() == Node.ELEMENT_NODE) {
- System.out
- .println(“=====================”);
- Element e = (Element) node;
- NodeList nodeList = e.getElementsByTagName(“name”);
- System.out.println(“Name: “
- + nodeList.item(0).getChildNodes().item(0)
- .getNodeValue());
- nodeList = e.getElementsByTagName(“grade”);
- System.out.println(“Grade: “
- + nodeList.item(0).getChildNodes().item(0)
- .getNodeValue());
- nodeList = e.getElementsByTagName(“age”);
- System.out.println(“Age: “
- + nodeList.item(0).getChildNodes().item(0)
- .getNodeValue());
- }
- }
- } else {
- System.exit(1);
- }
- }
- } catch (Exception e) {
- System.out.println(e);
- }
- }
- public static void main(String[] args) {
- XMLParser parser = new XMLParser();
- parser.getAllUserNames(“c:\\test.xml”);
- }
- }
使用iText JAR生成PDF
- import java.io.File;
- import java.io.FileOutputStream;
- import java.io.OutputStream;
- import java.util.Date;
- import com.lowagie.text.Document;
- import com.lowagie.text.Paragraph;
- import com.lowagie.text.pdf.PdfWriter;
- public class GeneratePDF {
- public static void main(String[] args) {
- try {
- OutputStream file = new FileOutputStream(new File(“C:\\Test.pdf”));
- Document document = new Document();
- PdfWriter.getInstance(document, file);
- document.open();
- document.add(new Paragraph(“Hello Kiran”));
- document.add(new Paragraph(new Date().toString()));
- document.close();
- file.close();
- } catch (Exception e) {
- e.printStackTrace();
- }
- }
- }
创建图片的缩略图 createThumbnail
- private void createThumbnail(String filename, int thumbWidth, int thumbHeight, int quality, String outFilename)
- throws InterruptedException, FileNotFoundException, IOException
- {
- // load image from filename
- Image image = Toolkit.getDefaultToolkit().getImage(filename);
- MediaTracker mediaTracker = new MediaTracker(new Container());
- mediaTracker.addImage(image, 0);
- mediaTracker.waitForID(0);
- // use this to test for errors at this point: System.out.println(mediaTracker.isErrorAny());
- // determine thumbnail size from WIDTH and HEIGHT
- double thumbRatio = (double)thumbWidth / (double)thumbHeight;
- int imageWidth = image.getWidth(null);
- int imageHeight = image.getHeight(null);
- double imageRatio = (double)imageWidth / (double)imageHeight;
- if (thumbRatio < imageRatio) {
- thumbHeight = (int)(thumbWidth / imageRatio);
- } else {
- thumbWidth = (int)(thumbHeight * imageRatio);
- }
- // draw original image to thumbnail image object and
- // scale it to the new size on-the-fly
- BufferedImage thumbImage = new BufferedImage(thumbWidth, thumbHeight, BufferedImage.TYPE_INT_RGB);
- Graphics2D graphics2D = thumbImage.createGraphics();
- graphics2D.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
- graphics2D.drawImage(image, 0, 0, thumbWidth, thumbHeight, null);
- // save thumbnail image to outFilename
- BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream(outFilename));
- JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
- JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(thumbImage);
- quality = Math.max(0, Math.min(quality, 100));
- param.setQuality((float)quality / 100.0f, false);
- encoder.setJPEGEncodeParam(param);
- encoder.encode(thumbImage);
- out.close();
- }