2017年7月7日 下午6:05
字符串数组转字符串
错误1
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| string = strings.toString();
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错误2
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| string = null;
for(int j = 0;j < strings.length;j++){
string += strings[j];
}
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输出：
null112155
正确
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| string = "";
for(int j = 0;j < strings.length;j++){
string += strings[j]+"\t";
}
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反射只能执行方法，但是得不到对象
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Class cla=PriorityFactory.class;
PriorityFactory pf=new PriorityFactory();
Method met1;
try {
met1 = cla.getMethod(method,null);
System.out.println(met1.invoke(pf,null));
} catch (Exception e) {
e.printStackTrace();
}
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java.lang.classnotfoundexception 反射
错的
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public String[][] getInt(){
String[][] strings = new String[3][1];
strings[0][0] = "query";
strings[1][0] = "buyBook";
strings[2][0] = "findBookById";
return strings;
}
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- 接口中属性下不来
- char[] a转字符串，toString是错的
- String.split(”\.”); java分割字符串
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| String[] strings = transferString(list);
System.out.println("aaa"+strings);
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| DefaultTableModel tableModel = (DefaultTableModel) table
.getModel();
tableModel.setRowCount(0);// 清除原有行
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解决方案：java - org.jdesktop.swingbinding.JTableBinding$BindingTableModel cannot be cast to javax.swing.table.DefaultTableModel - Stack Overflow
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| // 将变化的值赋给第9列
//对一个cell同时读写会造成循环
// table_2.setValueAt(string, row, 8);
@Override
public void tableChanged(TableModelEvent e) {
不能更改cell的值
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Java中普通代码块，构造代码块，静态代码块区别及代码示例 - sophine - 博客园
Demo2_Student.java
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| package delete;
class Student {
static {
System.out.println("Student 静态代码块");
}
{
System.out.println("Student 构造代码块");
}
public Student() {
System.out.println("Student 构造方法");
}
}
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Student.java
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| package delete;
class Demo2_Student {
static {
System.out.println("Demo2_Student静态代码块");
}
public static void main(String[] args) {
System.out.println("我是main方法");
Student s1 = new Student();
Student s2 = new Student();
}
}
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输出：
Demo2_Student静态代码块
我是main方法
Student 静态代码块
Student 构造代码块
Student 构造方法
Student 构造代码块
Student 构造方法