15. 创建ZIP和JAR文件

1. import java.util.zip.*;

2. import java.io.*;

3. publicclass ZipIt {

4. publicstaticvoid main(String args[]) throws IOException {

5. if (args.length < 2) {

6. System.err.println("usage: java ZipIt Zip.zip file1 file2 file3");

7. System.exit(-1);

8. }

9. File zipFile = new File(args[0]);

10. if (zipFile.exists()) {

11. System.err.println("Zip file already exists, please try another");

12. System.exit(-2);

13. }

14. FileOutputStream fos = new FileOutputStream(zipFile);

15. ZipOutputStream zos = new ZipOutputStream(fos);

16. int bytesRead;

17. byte[] buffer = newbyte[1024];

18. CRC32 crc = new CRC32();

19. for (int i=1, n=args.length; i < n; i++) {

20. String name = args[i];

21. File file = new File(name);

22. if (!file.exists()) {

23. System.err.println("Skipping: " + name);

24. continue;

25. }

26. BufferedInputStream bis = new BufferedInputStream(

27. new FileInputStream(file));

28. crc.reset();

29. while ((bytesRead = bis.read(buffer)) != -1) {

30. crc.update(buffer, 0, bytesRead);

31. }

32. bis.close();

33. // Reset to beginning of input stream

34. bis = new BufferedInputStream(

35. new FileInputStream(file));

36. ZipEntry entry = new ZipEntry(name);

37. entry.setMethod(ZipEntry.STORED);

38. entry.setCompressedSize(file.length());

39. entry.setSize(file.length());

40. entry.setCrc(crc.getValue());

41. zos.putNextEntry(entry);

42. while ((bytesRead = bis.read(buffer)) != -1) {

43. zos.write(buffer, 0, bytesRead);

44. }

45. bis.close();

46. }

47. zos.close();

48. }

49. }

16. 解析/读取XML 文件

XML文件

1. <?xmlversion="1.0"?>

2. <students>

3. <student>

4. <name>John</name>

5. <grade>B</grade>

6. <age>12</age>

7. </student>

8. <student>

9. <name>Mary</name>

10. <grade>A</grade>

11. <age>11</age>

12. </student>

13. <student>

14. <name>Simon</name>

15. <grade>A</grade>

16. <age>18</age>

17. </student>

18. </students>

Java代码：

1. ackage net.viralpatel.java.xmlparser;

2. import java.io.File;

3. import javax.xml.parsers.DocumentBuilder;

4. import javax.xml.parsers.DocumentBuilderFactory;

5. import org.w3c.dom.Document;

6. import org.w3c.dom.Element;

7. import org.w3c.dom.Node;

8. import org.w3c.dom.NodeList;

9. publicclass XMLParser {

10. publicvoid getAllUserNames(String fileName) {

11. try {

12. DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();

13. DocumentBuilder db = dbf.newDocumentBuilder();

14. File file = new File(fileName);

15. if (file.exists()) {

16. Document doc = db.parse(file);

17. Element docEle = doc.getDocumentElement();

18. // Print root element of the document

19. System.out.println("Root element of the document: "

20. + docEle.getNodeName());

21. NodeList studentList = docEle.getElementsByTagName("student");

22. // Print total student elements in document

23. System.out

24. .println("Total students: " + studentList.getLength());

25. if (studentList != null && studentList.getLength() > 0) {

26. for (int i = 0; i < studentList.getLength(); i++) {

27. Node node = studentList.item(i);

28. if (node.getNodeType() == Node.ELEMENT_NODE) {

29. System.out

30. .println("=====================");

31. Element e = (Element) node;

32. NodeList nodeList = e.getElementsByTagName("name");

33. System.out.println("Name: "

34. + nodeList.item(0).getChildNodes().item(0)

35. .getNodeValue());

36. nodeList = e.getElementsByTagName("grade");

37. System.out.println("Grade: "

38. + nodeList.item(0).getChildNodes().item(0)

39. .getNodeValue());

40. nodeList = e.getElementsByTagName("age");

41. System.out.println("Age: "

42. + nodeList.item(0).getChildNodes().item(0)

43. .getNodeValue());

44. }

45. }

46. } else {

47. System.exit(1);

48. }

49. }

50. } catch (Exception e) {

51. System.out.println(e);

52. }

53. }

54. publicstaticvoid main(String[] args) {

55. XMLParser parser = new XMLParser();

56. parser.getAllUserNames("c:\\test.xml");

57. }

58. }