15 10 14 Java jtextfielddata jbuttonwrite jlabelmessage void jbuttonwrite_actionperformed(actionevent e) { String Data=jTextFieldData.getText(); try { // Test1.txt fw FileWriter fw= new FileWriter("Test1.txt"); // fw BufferedWriter bw= new BufferedWriter(fw); // PrintWriter fout = new PrintWriter(bw); fout.print(" "+Data); // jlabelmessage.settext(" "); fout.close(); // catch(exception em) { jlabelmessage.settext(" "+em); 33
15 10 14 import java.awt.*; import java.awt.event.*; import javax.swing.*; import java.io.*; Test1.txt Test1.txt Test1.txt Java Java Java FileWriterBufferedWriter PrintWriter 34
15 10 14 p.33 FileWriter FileWriter fw= new FileWriter("Test1.txt"); FileWriter fw = new () FileWriter FileWriter() fw Test1.txt BufferedWriter BufferedWriter bw= new BufferedWriter(fw); bw PrintWriter PrintWriter print() println() PrintWriter PrintWriter fout = new PrintWriter(bw); PrintWriter fout = new PrintWriter(new BufferedWriter(new FileWriter("Test1.txt"))); FileWriter write() PrinWriter print() 35
15 10 14 println() close() trycatch FileWriter fw= new FileWriter("Test1.txt"); FileWriter IOException Exception Java Exception Exception Exception catch try { catch (Exception em{ catch(exception em) { jlabelmessage.settext(" "+em); catch () em Exception void jbuttonwrite_actionperformed(actionevent e) { String Data=jTextFieldData.getText(); try { fout.print(" "+Data); // fout.print( "); jlabelmessage.settext(" "); 36
15 10 14 Test1.txt print() Test1.txt print() println() fout.println(" "+Data); // fout.print( "); println() () 3-1 fout.println(" "+Data); // fout.println(" "); int a=2,b=5; fout.println("a="+a+" b="+b); fout.println("a+b="+(a+b)); jlabelmessage.settext(" "); Test1.txt Test1.txt a=2 b=5 a+b=7 37
15 10 14 Java int a=2; String Ans="a="+a; Ans a=2 Java int a=2; String Ans="a/4="+(a/4.0); Ans a/4=0.5 38
15 10 14 3-2 jtextfielddata jlabelmessage jbuttonwrite Swing Containers JFileChooser UI JFileChooser IOFile IOFile 39
15 10 14 void jbuttonwrite_actionperformed(actionevent e) { String Data=jTextFieldData.getText(); try { // jfilechooser1.showopendialog(this); // File FName=jFileChooser1.getSelectedFile(); // PrintWriter fout=new PrintWriter(new BufferedWriter (new FileWriter(FName))); fout.println(" "+Data); // jlabelmessage.settext(" "); fout.close(); // catch(exception em) { jlabelmessage.settext(" "+em); import java.io.*; IOFile 40
15 10 14 output.txt output.txt IOFile output.txt JFileChooser output.txt showopendialog() () this getselectedfile() File FName "output.txt" 41
15 10 14 3-2 output.txt 3-3 jlabelmessage jtextfielddata jbuttonread 3-2 p.39 JFileChooser UI void jbuttonread_actionperformed(actionevent e) { String Data; try { jfilechooser1.showopendialog(this); File FName=jFileChooser1.getSelectedFile(); BufferedReader fin=new BufferedReader (new FileReader(FName)); Data=fin.readLine(); // jtextfielddata.settext(data); // fin.close(); jlabelmessage.settext(" "); catch (Exception em) { jlabelmessage.settext(" "+em); import java.io.*; 42
15 10 14 fin PrintWriter readline() FName 3-2 output.txt output.txt 43
15 10 14 3-4 input.txt 55 60 92 38 71 HP input.txt IOFile [ ] jbuttonread jtextfieldavg jbuttonavg input.txt 44
15 10 14 3-3 6-12 int Tokuten[]=new int[5]; // int Num; // void jbuttonread_actionperformed(actionevent e) { String Data; try { jfilechooser1.showopendialog(this); File FName=jFileChooser1.getSelectedFile(); BufferedReader fin=new BufferedReader (new FileReader(FName)); // Num=5; // for (int i=0;i<num;i++) { Data=fin.readLine(); Tokuten[i]=Integer.parseInt(Data); jlabelmessage.settext(" "); fin.close(); catch (Exception em) { jlabelmessage.settext(" "+em); void jbuttonavg_actionperformed(actionevent e) { // int sum=0; for (int i=0;i<num;i++) { sum=sum+tokuten[i]; double Avg= sum/(double)(num); jtextfieldavg.settext(string.valueof(avg)); 45
15 10 14 Tokuten Num Tokuten[i] Tokuten[i] Java Num p.72 46
15 10 14 3-4 3-4 3-5 3-4 int Tokuten[]=new int[100]; // int Num; // void jbuttonread_actionperformed(actionevent e) { String Data; try { jfilechooser1.showopendialog(this); File FName=jFileChooser1.getSelectedFile(); BufferedReader fin=new BufferedReader (new FileReader(FName)); // int i=0; while ((Data=fin.readLine())!=null) { Tokuten[i]=Integer.parseInt(Data); i++; Num=i; // jlabelmessage.settext(" "); fin.close(); catch (Exception em) { jlabelmessage.settext(" "+em); 100 readline() null null while ((Data=fin.readLine())!=null) 47
15 10 14 Data null while i 0 3-6 3-5 jbuttonmax jtextfieldmax void jbuttonmax_actionperformed(actionevent e) { int Max=Tokuten[0]; for(int i=1; i<num;i++) { if(tokuten[i]>max) { Max=Tokuten[i]; jtextfieldmax.settext(string.valueof(max)); 48
15 10 14 3-A 3-6 3-B HP score.txt <score.txt> 3-A 55 90 85 38 80 100 150 49
15 10 14 3-C 3-B 50 score.txt 50