试题：
源码（本源码是个人原创，正确性未考证）：
1.dababase.properties文件：
0=1 1 1
1=1 1 1 1 2 3
2=2 3 4 1 1 1
3=3 4 5
4=1 1 1 1 2 3
2.源代码：
package plane;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;
import java.util.Scanner;
class Plane {
// 初始化，记录数据 输入数据，记录到properties文件中,给予一个标记表示输入完毕。
public Plane() throws Exception {
List<String> list = new ArrayList<String>();
Scanner sc = new Scanner(System.in);
// 输入exit结束输入
while (true) {
System.out.print("plane1:");
String line = sc.nextLine();
if (line.equals("exit".trim()))
break;
list.add(line);
}
OutputStream output = new FileOutputStream("dababase.properties");
Properties props = new Properties();
for (int i = 0; i < list.size(); i++) {
props.setProperty(i + "", list.get(i));
}
props.store(output, null);
}
// 操作数据
public static String print(int id) throws Exception {
Properties props = new Properties();
InputStream input = new FileInputStream("dababase.properties");
props.load(input);
String data = null;
try {
data = props.getProperty(id + "");
String[] nums = data.split("\\s+");
if (nums.length == 3) {
if (id == 0) {
return " " + nums[0] + " " + nums[1] + " " + nums[2];
} else {
return "error";
}
} else {
String[] array = new String[3];
array[0] = (Integer.parseInt(nums[0]) + Integer
.parseInt(nums[3])) + "";
array[1] = (Integer.parseInt(nums[1]) + Integer
.parseInt(nums[4])) + "";
array[2] = (Integer.parseInt(nums[2]) + Integer
.parseInt(nums[5])) + "";
return " " + array[0] + " " + array[1] + " " + array[2];
}
} catch (Exception e) {
return "noId";
}
}
}
public class Test {
public static void main(String[] args) throws Exception {
new Plane();
int xx = 0; //判断标记，如果出现error,即以后不管输入什么,都是Error
while (true) {
Scanner sc = new Scanner(System.in);
System.out.print("输入id:");
int id = sc.nextInt();
String data = Plane.print(id);
if (data == "error") {
xx = 1;
System.out.println("Error: " + id);
} else if (data == "noId") {
if (xx == 0) {
System.out.println("Cannot find " + id);
} else {
System.out.println("Error: " + id);
}
} else {
if (xx == 0) {
System.out.println("panle1 " + id + data);
} else {
System.out.println("Error: " + id);
}
}
}
}
}
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本文由安康学院“雨季”原创！