我在尝试创建一个线程构造函数时会遇到一些问题，该构造函数将接受文件名和要写入文件的二维数据数组。线程运行方法假设将该二维数组写入该文件，然后为courses.txt文件和students.txt文件实例化该线程。我试图通过使用多线程应用程序来做到这一点。 2D数组将是一个2D String数组，正如我已经在代码上创建的那样。我已经将数据硬编码到2D String数组中，但我对如何将该数组和文件名传递给将写入该文件的线程感到困惑。我知道我可以使用一个run（）方法编写一个线程类，该方法将写入任一文件。如何在WriteFiles.java的main（）中创建该线程的两个实例，然后传递一个Student数据并传递另一个Course数据？
这是我到目前为止的代码，并且非常喜欢一些指导：
import java.util.*;
import java.io.*;
class WriteFiles implements Runnable
{
static final String FILE = "courses.txt";
static final String FILE2 = "students.txt";
BufferedWriter bw;
Thread thread[] = new Thread[2];
private String studentList[][];
private String courseList[][];
public WriteFiles()
{
try
{
bw = new BufferedWriter( new FileWriter( FILE ) );
bw = new BufferedWriter( new FileWriter( FILE2 ) );
}
catch( FileNotFoundException fnfe )
{
System.out.println( fnfe );
System.exit( 1 );
}
catch( IOException ioe )
{
System.out.println( ioe );
System.exit( 2 );
}
}
public void writeFile( String str )
{
try{
bw.write( str );
} catch( IOException ioe ){
System.out.println( ioe );
}
}
public void run()
{
String studentList[][] = {
{"Python","INSY 3300","530-650 MW","1,3"},
{"Networking","INSY 3303","530-650 TR","1,3"},
{"DBMS","INSY 3304","900-950 MWF","1,3"},
{"Analysis&Design","INSY 3305","700-820 TR","1,3"},
{"Java I","INSY 4305","700-820 TR","1,3"},
{"Java II","INSY 4306","530-650 TR","1,3"},
{"Mobile App","INSY 4308","200-320 TR","1,3"},
{"Web Development","INSY 4315","1000-1050 MWF","1,3"},
{"Resource Management","INSY 4325","100-220 TR","1,3"}
};
String courseList[][] = {
{"US","NONRESIDENT","123456","Jones","123 Cooper St","Arlington","Texas","76019","12345"},
{"INT","ACTIVE","A-654789","Degrassey","18 Love Lane","Dallas","Texas","75052","67123"},
{"INT","INACTIVE","A-543891","Franco","1201 Trail Road","Euless","Texas","74032","19814"},
{"US","RESIDENT","345123","Hughes","1803 Division","Fort Worth","Texas","76034","674532"},
{"US","RESIDENT","988776","Cooper","111 Marsh Lane","Bedford","Texas","76111","90906"},
{"INT","INACTIVE","B-577463","Patel","2218 Border St","Arlington","Texas","76015","81832"}
};
}
public void writeCourses()
{
for (Student s:studentList){
System.out.print(s.toString());
}
}
public void writeStudents()
{
for (Course c:courseList){
System.out.print(c.toString());
}
}
public static void main( String arg[] )
{
WriteFiles myTread = new WriteFiles();
myTread.writeCourses();
myTread.writeStudents();
}
}
最终的students.txt输出假设看起来像这样;按数据分割：
US; NONRESIDENT; 123456; Jones; 123 Cooper St; Arlington; Texas; 76019; 12345 INT; ACTIVE; A-654789; Degrassey; 18 Love Lane; Dallas; Texas; 75052; 67123 INT; INACTIVE; A-543891; Franco; 1201 Trail Road; Euless; Texas; 74032; 19814 US; RESIDENT; 345123; Hughes; 1803 Division; Fort Worth; Texas; 76034; 674532 US; RESIDENT; 988776; Cooper; 111 Marsh Lane; Bedford; Texas; 76111; 90906 INT; INACTIVE; B-577463; Patel; 2218 Border St; Arlington; Texas; 76015; 81832
最终的course.txt输出假设看起来像这样;按数据分割：
Python; INSY 3300; 530-650 MW; 1; 3 网络; INSY 3303; 530-650 TR; 1; 3 DBMS; INSY 3304; 900-950 MWF; 1; 3 分析与设计; INSY 3305; 700-820 TR; 1; 3 Java I; INSY 4305; 700-820 TR; 1; 3 Java II; INSY 4306; 530-650 TR; 1; 3 移动应用; INSY 4308; 200-320 TR; 1; 3 Web开发; INSY 4315; 1000-1050 MWF; 1; 3 资源管理; INSY 4325; 100-220 TR; 1; 3
我没有问题让这个方法工作成功，但是我现在正在尝试使用多线程应用程序的不同方法。这是一个没有线程的工作输出：
import java.util.*;
import java.io.*;
public class WriteFiles {
private static Formatter output;
private static Scanner input;
public static void main(String[] args) {
ArrayList<Student> studentList = new ArrayList<Student>();
writeTextFile1();
for (Student s:studentList){
System.out.print(s.toString());
}
ArrayList<Course> courseList = new ArrayList<Course>();
writeTextFile();
for (Course c:courseList){
System.out.print(c.toString());
}
}
public static void writeTextFile(){
try{
output = new Formatter("courses.txt");
output.format("%s;%s;%s;%d;%d%n","Python","INSY 3300","530-650 MW",1,3);
output.format("%s;%s;%s;%d;%d%n","Networking","INSY 3303","530-650 TR",1,3);
output.format("%s;%s;%s;%d;%d%n","DBMS","INSY 3304","900-950 MWF",1,3);
output.format("%s;%s;%s;%d;%d%n","Analysis&Design","INSY 3305","700-820 TR",1,3);
output.format("%s;%s;%s;%d;%d%n","Java I","INSY 4305","700-820 TR",1,3);
output.format("%s;%s;%s;%d;%d%n","Java II","INSY 4306","530-650 TR",1,3);
output.format("%s;%s;%s;%d;%d%n","Mobile App","INSY 4308","200-320 TR",1,3);
output.format("%s;%s;%s;%d;%d%n","Web Development","INSY 4315","1000-1050 MWF",1,3);
output.format("%s;%s;%s;%d;%d%n","Resource Management","INSY 4325","100-220 TR",1,3);
output.close();
}
catch(IOException ioe){
ioe.printStackTrace();
}
}
public static void writeTextFile1(){
try{
output = new Formatter("students.txt");
output.format("%s;%s;%s;%s;%s;%s;%s;%d;%d%n","US","NONRESIDENT","123456","Jones","123 Cooper St","Arlington","Texas",76019,12345);
output.format("%s;%s;%s;%s;%s;%s;%s;%d;%d%n","INT","ACTIVE","A-654789","Degrassey","18 Love Lane","Dallas","Texas",75052,67123);
output.format("%s;%s;%s;%s;%s;%s;%s;%d;%d%n","INT","INACTIVE","A-543891","Franco","1201 Trail Road","Euless","Texas",74032,19814);
output.format("%s;%s;%s;%s;%s;%s;%s;%d;%d%n","US","RESIDENT","345123","Hughes","1803 Division","Fort Worth","Texas",76034,674532);
output.format("%s;%s;%s;%s;%s;%s;%s;%d;%d%n","US","RESIDENT","988776","Cooper","111 Marsh Lane","Bedford","Texas",76111,90906);
output.format("%s;%s;%s;%s;%s;%s;%s;%d;%d%n","INT","INACTIVE","B-577463","Patel","2218 Border St","Arlington","Texas",76015,81832);
output.close();
}
catch(IOException ioe){
ioe.printStackTrace();
}
}
}
答案 0 :(得分：0)
我对如何将该数组和文件名传递给将写入文件的线程感到有点困惑
除非我不理解这个问题，否则简短的回答是关于构造函数的参数。您可以为String[][]传递内容，并输入String作为输出文件名。
public class WriteFile implements Runnable {
private final String[][] contentLines;
private final String outputFilename;
public WriteFile(String[][] contentLines, String outputFilename) {
this.contentLines = contentLines;
this.outputFilename = outputFilename;
}
public void run() {
// write the content to the file-name
BufferedWriter bw = new BufferedWriter(new FileWriter(outputFilename));
try {
for (String[] contentLine : contentLines) {
...
}
} finally {
bw.close();
}
}
}
然后你会这样说：
Thread studentThread = new Thread(new WriteFile(studentList, "students.txt"));
studentThread.start();
Thread courseThread = new Thread(new WriteFile(courseList, "courses.txt"));
courseThread.start();
// now wait for the threads to finish writing
studentThread.join();
courseThread.join();
如果要将Student或Course个对象传入此runnable，则需要创建一个不同的runnable来处理正在编写的每种类型的数据。
// student file writer runnable
Thread studentThread = new Thread(new WriteStudentFile(studentList, "students.txt"));
// course file writer runnable
Thread courseThread = new Thread(new WriteCourseFile(courseList, "courses.txt"));
答案 1 :(得分：0)
我刚刚发现我的arraylist都错了。我要将它全部视为一条线，但在我的GUI程序中仍然是2D bc我要分割它;术语
String studentList[][] = {
{"Python;INSY 3300;530-650 MW;1,3"},
{"Networking;INSY 3303;530-650 TR;1,3"},
{"DBMS;INSY 3304;900-950 MWF;1,3"},
{"Analysis&Design;INSY 3305;700-820 TR;1,3"},
{"Java I;INSY 4305","700-820 TR","1,3"},
{"Java II","INSY 4306;530-650 TR;1,3"},
{"Mobile App;INSY 4308;200-320 TR;1,3"},
{"Web Development;INSY 4315;1000-1050 MWF;1,3"},
{"Resource Management;INSY 4325;100-220 TR;1,3"}
};
String courseList[][] = {
{"US;NONRESIDENT;23456;Jones;123 Cooper St;Arlington;Texas;76019;12345"},
{"INT;ACTIVE;A-654789;Degrassey;18 Love Lane;Dallas;Texas;75052;67123"},
{"INT;INACTIVE;A-543891;Franco;1201 Trail Road;Euless;Texas;74032;19814"},
{"US;RESIDENT;345123;Hughes;1803 Division;Fort Worth;Texas;76034;674532"},
{"US;RESIDENT;988776;Cooper;111 Marsh Lane;Bedford;Texas;76111;90906"},
{"INT;INACTIVE;B-577463;Patel;2218 Border St;Arlington;Texas;76015;81832"}
};
我还是有点困惑。我在主编写线程数组吗？
答案 2 :(得分：0)
解决了！对于那些想要引用的人，如果碰巧遇到类似的问题，我将分享代码：
//Donovan
package hw2;
//Importing Java imports that are required for the program to execute properly
import java.util.concurrent.Executors;
import java.util.concurrent.ExecutorService;
import java.util.*;
import java.io.*;
//Creating my public & private class for WriteFiles that uses Runnable, including Formatter
public class WriteFiles implements Runnable{
private String threadDonovan;
private String[][] arrayDonovan;
Formatter output;
//Creating a WriteFiles which will accept a thread as a String and a 2D ArrayList for later Execution
public WriteFiles(String str, String arrays[][])
{
//Create a string an array for later use in the run()
threadDonovan = str;
arrayDonovan = arrays;
}
//Time to run a try and catch methods
public void run()
{
//First have to try a few things
try
{
//create a Formatter from my Thread
output = new Formatter(threadDonovan);
//Running 2 for loops to output the correct information into the .txt files
for (int i = 0; i < arrayDonovan.length; i++)
{
for (int j = 0; j < arrayDonovan[i].length; j++)
{
//Proper Formatting is Required so the .txt files
//are written properly so they're the same way as HW1
//and so the GUI doesn't run into any problems
output.format("%s%n",arrayDonovan[i][j]);
}
}
//Once the Data is written, have to close the Formatter
output.close();
}
//Now have to catch a few errors and print them to debug if needed
catch( IOException ioe )
{
ioe.printStackTrace();
System.out.println(ioe);
System.exit(2);
}
}
//creating the main which will have the 2D ArrayList and the Executor Service
public static void main(String[] args) throws InterruptedException
{
//create my 2D ArrayList for Students
String studentList[][] = {
{"US;NONRESIDENT;23456;Jones;123 Cooper St;Arlington;Texas;76019;12345"},
{"INT;ACTIVE;A-654789;Degrassey;18 Love Lane;Dallas;Texas;75052;67123"},
{"INT;INACTIVE;A-543891;Franco;1201 Trail Road;Euless;Texas;74032;19814"},
{"US;RESIDENT;345123;Hughes;1803 Division;Fort Worth;Texas;76034;674532"},
{"US;RESIDENT;988776;Cooper;111 Marsh Lane;Bedford;Texas;76111;90906"},
{"INT;INACTIVE;B-577463;Patel;2218 Border St;Arlington;Texas;76015;81832"}
};
//create my 2D ArrayList for Courses
String courseList[][] = {
{"Python;INSY 3300;530-650 MW;1;3"},
{"Networking;INSY 3303;530-650 TR;1;3"},
{"DBMS;INSY 3304;900-950 MWF;1;3"},
{"Analysis&Design;INSY 3305;700-820 TR;1;3"},
{"Java I;INSY 4305;700-820 TR;1;3"},
{"Java II;INSY 4306;530-650 TR;1;3"},
{"Mobile App;INSY 4308;200-320 TR;1;3"},
{"Web Development;INSY 4315;1000-1050 MWF;1;3"},
{"Resource Management;INSY 4325;100-220 TR;1;3"}
};
//What will be created once ExecutorService Starts for Students
WriteFiles studentFile = new WriteFiles("students.txt",studentList);
//What will be created once ExecutorService Starts for Courses
WriteFiles courseFile = new WriteFiles("courses.txt",courseList);
//Begin the Executor Service
ExecutorService executorService = Executors.newCachedThreadPool();
//start the first Task/Thread to create students.txt from the studentList 2D ArrayLIst
executorService.execute(studentFile);
//start the first Task/Thread to create courses.txt from the courseList 2D ArrayLIst
executorService.execute(courseFile); //start task 2
//End the Executor Service
executorService.shutdown();
}
}