如果我使用其他类中的方法，则我的GUIForm会出错。你们能告诉我，我做的是对的吗？一些修改表示赞赏。谢谢！这是我的代码：
的 Books.java 的
package exer_sec;
public class Books {
private String author;
private String title;
private int numOfPages;
private String[] arr_author;
private String[] arr_title;
private long[] arr_pages;
public Books(String[] author, String[] title, long[] numOfPages) {
this.arr_author = author;
this.arr_title = title;
this.arr_pages = numOfPages;
}
public Books() {
this.author = "JK Rowling";
this.title = "Harry Potter";
this.numOfPages = 223;
}
public String[] getAuthor() {
return arr_author;
}
public void setAuthor(String[] author) {
this.arr_author = author;
}
public String[] getTitle() {
return arr_title;
}
public void setTitle(String[] title) {
this.arr_title = title;
}
public long[] getNumOfPages() {
return arr_pages;
}
public void setNumOfPages(long[] numOfPages) {
this.arr_pages = numOfPages;
}
@Override
public String toString() {
return "Author = " + arr_author + " | Title = " + arr_title + " | Pages = " + arr_pages;
}
public void displayAuthors() {
System.out.print("Authors: ");
if (arr_author.length >= 1) {
System.out.print(arr_author[0]);
}
for (int i = 1; i < arr_author.length; i++)
System.out.print(", " + arr_author[i] );
System.out.println("");
/*
for (int i = 1; i < arr_author.length; i++)
System.out.println(arr_author[i] );
*/
}
public void displayTitles() {
System.out.print("Titles: ");
if (arr_title.length >= 1) {
System.out.print(arr_title[0]);
}
for (int i = 1; i < arr_title.length; i++)
System.out.print(", " + arr_title[i] );
System.out.println("");
}
public void displayPages() {
System.out.print("Pages: ");
if (arr_pages.length >= 1) {
System.out.print(arr_pages[0]);
}
for (int i = 1; i < arr_pages.length; i++)
System.out.print(", " + arr_pages[i] );
System.out.println("");
}
public void display1() {
displayAuthors();
displayTitles();
displayPages();
}
public void display2(Books[] x) {
for (int i = 0; i < x.length; i++) {
System.out.println(x[i]);
}
}
}
的 Main.java 的
package exer_sec;
public class Main {
public static void main(String[] args) {
Books b1 = new Books();
BubbleSort bub = new BubbleSort();
String[] authors = {"James Dashner", "Veronica Roth", "Joanne Rowling",
"Suzanne Collins", "Rick Riordan"};
String[] titles = {"Maze Runner", "Divergent", "Harry Potter",
"Hunger Games", "Percy Jackson"};
long[] pages = {374, 487, 309, 391, 384};
b1.setAuthor(authors);
b1.setTitle(titles);
b1.setNumOfPages(pages);
System.out.print("OUTPUT \n");
b1.display1();
System.out.print("\nBUBBLE SORT \n");
bub.sortString(authors);
bub.sortString(titles);
bub.sortNum(pages);
b1.display1();
}
}
的 BubbleSort.java 的
package exer_sec;
public class BubbleSort extends Books {
public void sortString(String[] x) {
int j;
String temp;
boolean flag = true;
while (flag) {
flag = false;
for (j = 0; j < x.length - 1; j++) {
if (x[j].compareTo(x[j + 1]) > 0) {
temp = x[j];
x[j] = x[j + 1];
x[j + 1] = temp;
flag = true;
}
}
}
}
public void sortNum(long[] x) {
int j;
int temp;
boolean flag = true;
while (flag) {
flag = false;
for (j = 0; j < x.length - 1; j++) {
if (x[j] > x[j + 1]) {
temp = (int) x[j];
x[j] = x[j + 1];
x[j + 1] = temp;
flag = true;
}
}
}
}
}
的 Form.java 的 GUI。这是用于执行操作的按钮，但它不会起作用T_T
package exer_sec;
import java.util.Arrays;
public class Form extends javax.swing.JFrame {
Books b1 = new Books();
public Form() {
initComponents();
}
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jPanel1 = new javax.swing.JPanel();
jScrollPane1 = new javax.swing.JScrollPane();
txtarea_beforesort = new javax.swing.JTextArea();
jLabel2 = new javax.swing.JLabel();
jPanel2 = new javax.swing.JPanel();
jScrollPane2 = new javax.swing.JScrollPane();
txtarea_aftersort = new javax.swing.JTextArea();
jLabel3 = new javax.swing.JLabel();
jButton1 = new javax.swing.JButton();
jButton2 = new javax.swing.JButton();
jPanel3 = new javax.swing.JPanel();
jScrollPane3 = new javax.swing.JScrollPane();
jTextArea3 = new javax.swing.JTextArea();
jLabel1 = new javax.swing.JLabel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jPanel1.setBackground(new java.awt.Color(204, 204, 255));
jPanel1.setBorder(javax.swing.BorderFactory.createLineBorder(new java.awt.Color(0, 0, 0), 2));
txtarea_beforesort.setColumns(20);
txtarea_beforesort.setFont(new java.awt.Font("Monospaced", 0, 12)); // NOI18N
txtarea_beforesort.setRows(5);
jScrollPane1.setViewportView(txtarea_beforesort);
jLabel2.setFont(new java.awt.Font("Calibri", 0, 11)); // NOI18N
jLabel2.setText("BEFORE SORTING...");
javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addContainerGap()
.addComponent(jScrollPane1)
.addContainerGap())
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
.addContainerGap(135, Short.MAX_VALUE)
.addComponent(jLabel2)
.addGap(128, 128, 128))
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addComponent(jLabel2)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 144, Short.MAX_VALUE)
.addGap(14, 14, 14))
);
jPanel2.setBackground(new java.awt.Color(255, 204, 204));
jPanel2.setBorder(javax.swing.BorderFactory.createLineBorder(new java.awt.Color(0, 0, 0), 2));
txtarea_aftersort.setColumns(20);
txtarea_aftersort.setFont(new java.awt.Font("Monospaced", 0, 12)); // NOI18N
txtarea_aftersort.setRows(5);
jScrollPane2.setViewportView(txtarea_aftersort);
jLabel3.setFont(new java.awt.Font("Calibri", 0, 11)); // NOI18N
jLabel3.setText("AFTER SORTING...");
javax.swing.GroupLayout jPanel2Layout = new javax.swing.GroupLayout(jPanel2);
jPanel2.setLayout(jPanel2Layout);
jPanel2Layout.setHorizontalGroup(
jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel2Layout.createSequentialGroup()
.addContainerGap()
.addComponent(jScrollPane2)
.addContainerGap())
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel2Layout.createSequentialGroup()
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jLabel3)
.addGap(132, 132, 132))
);
jPanel2Layout.setVerticalGroup(
jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel2Layout.createSequentialGroup()
.addComponent(jLabel3)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jScrollPane2, javax.swing.GroupLayout.DEFAULT_SIZE, 144, Short.MAX_VALUE)
.addContainerGap())
);
jButton1.setFont(new java.awt.Font("Calibri", 0, 11)); // NOI18N
jButton1.setText("Bubble Sort");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
jButton2.setFont(new java.awt.Font("Calibri", 0, 11)); // NOI18N
jButton2.setText("Selection Sort");
jPanel3.setBackground(new java.awt.Color(255, 255, 204));
jTextArea3.setColumns(20);
jTextArea3.setFont(new java.awt.Font("Monospaced", 0, 12)); // NOI18N
jTextArea3.setRows(5);
jScrollPane3.setViewportView(jTextArea3);
javax.swing.GroupLayout jPanel3Layout = new javax.swing.GroupLayout(jPanel3);
jPanel3.setLayout(jPanel3Layout);
jPanel3Layout.setHorizontalGroup(
jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel3Layout.createSequentialGroup()
.addContainerGap()
.addComponent(jScrollPane3, javax.swing.GroupLayout.PREFERRED_SIZE, 0, Short.MAX_VALUE)
.addContainerGap())
);
jPanel3Layout.setVerticalGroup(
jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel3Layout.createSequentialGroup()
.addContainerGap()
.addComponent(jScrollPane3, javax.swing.GroupLayout.DEFAULT_SIZE, 231, Short.MAX_VALUE)
.addContainerGap())
);
jLabel1.setFont(new java.awt.Font("Calibri", 0, 11)); // NOI18N
jLabel1.setText("PAGADUAN_exer_02");
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jPanel2, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
.addComponent(jPanel3, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jButton2, javax.swing.GroupLayout.DEFAULT_SIZE, 131, Short.MAX_VALUE)
.addComponent(jButton1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
.addContainerGap())
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addGap(0, 20, Short.MAX_VALUE)
.addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 121, javax.swing.GroupLayout.PREFERRED_SIZE))))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addComponent(jButton1)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jButton2)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jPanel3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addComponent(jLabel1))
.addGroup(layout.createSequentialGroup()
.addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jPanel2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addContainerGap(13, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
txtarea_beforesort.append(b1.display1());
//txtarea_beforesort.setText(b1.display1());
}
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(Form.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(Form.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(Form.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(Form.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Form().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton jButton1;
private javax.swing.JButton jButton2;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JPanel jPanel1;
private javax.swing.JPanel jPanel2;
private javax.swing.JPanel jPanel3;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JScrollPane jScrollPane2;
private javax.swing.JScrollPane jScrollPane3;
private javax.swing.JTextArea jTextArea3;
private javax.swing.JTextArea txtarea_aftersort;
private javax.swing.JTextArea txtarea_beforesort;
// End of variables declaration
}
答案 0 :(得分：0)
您的方法不会返回任何内容，因为返回类型为void。
将您的方法更改为字符串;
public String sortString(String[] x) {
int j;
String temp;
boolean flag = true;
while (flag) {
flag = false;
for (j = 0; j < x.length - 1; j++) {
if (x[j].compareTo(x[j + 1]) > 0) {
temp = x[j];
x[j] = x[j + 1];
x[j + 1] = temp;
flag = true;
}
}
}
return x;
}
答案 1 :(得分：0)
所有这四种方法都应该返回一个String而不是void并打印
public void display1() { // 1
displayAuthors(); // 2
displayTitles(); // 3
displayPages(); // 4
}
实施例
public String display1() {
return displayAuthors() + " " + displayTitles() + " " + displayPages();
}
public String displayTitles() {
StringBuilder sb = new StringBuilder();
sb.append("Titles: ");
if (arr_title.length >= 1) {
sb.append(arr_title[0]);
}
for (int i = 1; i < arr_title.length; i++)
sb.append(", " + arr_title[i] );
return sb.toString();
}
public String displayPages() {
StringBuilder sb = new StringBuilder();
sb.append("Pages: ");
if (arr_pages.length >= 1) {
sb.append(arr_pages[0]);
}
for (int i = 1; i < arr_pages.length; i++)
sb.append(", " + arr_pages[i] );
return sb.toString();
}
// and finally your displayAutors