在Java中使用两个OutputStreams和BufferedWriter

我很好奇是否有人能帮我理解我做错了什么。我只是在学习如何在Java中使用OutputStreams和BufferedWriter，我不确定我是否做对了。我知道如何使用一个OutputStream和BufferedWriter，但我的问题是试图在一个类中使用其中的两个

现在，我遇到的主要错误是在我的上下层阶级中，在我的try/catch语句和if/else语句之间，我不确定我做错了什么。所以我非常感谢你们在这件事上给我的任何帮助，以及帮助我理解如何同时使用其中两件物品

这些是我遇到的错误，因为我还是Java的初学者，所以我不太清楚这里发生了什么：

第40行错误：“）”应为 如果（creditsEarned>60 writerUpper.write）{

第40行错误：不是语句 如果（creditsEarned>60 writerUpper.write）{

第40行错误：应为“；” 如果（creditsEarned>60 writerUpper.write）{

第43行错误：“else”不带“if” else（writerLower.write）{

第43行错误：不是语句 else（writerLower.write）{

第43行错误：应为“；” else（writerLower.write）{

这是我的密码：

import java.nio.file.*;
import java.io.*;
import static java.nio.file.StandardOpenOption.*;
import java.nio.file.attribute.BasicFileAttributes;
import java.nio.file.attribute.FileTime;
import java.util.InputMismatchException;
import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class LowerAndUpper {


public static void main(String[] args) {
    Path file1 =
            Paths.get("C:/temp/lowerclassman.txt");
    Path file2 =
            Paths.get("C:/temp/upperclassman.txt");
    String s = "";
    String delimiter = ",";
    int id;
    String name;
    double creditsEarned;
    final int QUIT = 999;
    try {
        OutputStream output = new BufferedOutputStream(Files.newOutputStream(file1));
        BufferedWriter writerUpper = new BufferedWriter(new OutputStreamWriter(output));
        OutputStream output2 = new BufferedOutputStream(Files.newOutputStream(file2));
        BufferedWriter writerLower = new BufferedWriter(new OutputStreamWriter(output2));
        while (true) {
            id = Validate.collectInt("Enter student ID number or " + QUIT
                    + " to quit >> ");
            if (id == QUIT) {
                break;
            }
            name = Validate.collectString(2, "Enter student name "
                    + id + " >> ");
            creditsEarned = Validate.collectWage("Enter credit hours >> ");
            s = id + delimiter + name + delimiter + creditsEarned;
            if (creditsEarned>60 writerUpper.write){
              System.out.println("Student is a Lowerclassman");

            else (writerLower.write){
 System.out.println("Student is an Upperclassman");
}
        }
           writerUpper.write(s, 0, s.length());
            r.newLine();

        } //end while


        writer.close();
        writer2.close();
    } catch (Exception e) {
        System.out.println("Message: " + e);
    }

}
}


// **************************************************************************

class Validate {

public static int collectInt(String messageIn) {
    Scanner input = new Scanner(System.in);
    int intOut = 0;
    boolean valid = true;

    System.out.println(messageIn);
    while (valid) {
        try {
            intOut = input.nextInt();
            valid = false;
        } catch (InputMismatchException ie) {
            input.nextLine();
            System.out.println("You must enter a whole number");
        } //end catch
    } //end while

    return intOut;

}//end collectInt method

//*************************************************************************
public static String collectString(int strLen, String messageIn) {
    Scanner input = new Scanner(System.in);
    String strOut = "";
    boolean valid = true;

    System.out.println(messageIn);
    while (valid) {
        try {
            strOut = input.nextLine();
            if (strOut.length() < strLen) {
                throw new Exception();
            }
            valid = false;
        } catch (Exception e) {
            System.out.printf("You must be at least %s characters\n",
                    strLen);
        } //end catch
    } //end while

    return strOut;
} //end collectString method

//*************************************************************************
public static String collectZipcode(String messageIn) {
    Scanner input = new Scanner(System.in);
    String strOut = "";
    boolean valid = true;

    System.out.println(messageIn);
    while (valid) {
        try {
            strOut = input.nextLine();
            Integer.parseInt(strOut);
            if (strOut.length() != 5) {
                throw new Exception();
            }
            valid = false;
        } catch (NumberFormatException ne) {
            System.out.println("Please enter a valid zip code");
        } catch (Exception e) {

            System.out.printf("A zip code should be 5 numbers long");
        } //end catch
    } //end while

    return strOut;
}//end collectZipcode method

//*************************************************************************
public static String collectEmail(String messageIn) {
    String expression = "^[\\w\\.-]+@([\\w\\-]+\\.)+[A-Z]{2,4}$";
    Pattern pattern = Pattern.compile(expression, Pattern.CASE_INSENSITIVE);

    Scanner input = new Scanner(System.in);
    String strOut = "";
    boolean valid = true;

    System.out.println(messageIn);
    while (valid) {
        try {
            strOut = input.nextLine();
            CharSequence emailChk = strOut;
            Matcher matcher = pattern.matcher(emailChk);
            if (!matcher.matches()) {
                throw new Exception();
            }
            valid = false;
        } catch (Exception e) {
            System.out.printf("Please try again with a valid email "
                    + "address\n");
        } //end catch
    } //end while

    return strOut;

}//end collectEmail method

//*************************************************************************
public static Double collectWage(String messageIn) {

    Scanner input = new Scanner(System.in);
    double dblOut = 0;
    boolean valid = true;

    System.out.println(messageIn);
    while (valid) {
        try {
            dblOut = input.nextDouble();
            valid = false;
        } catch (InputMismatchException ie) {
            input.nextLine();
            System.out.println("You must enter a whole number ");
        } //end catch
    } //end while

    return dblOut;

}//end collectInt method

//*************************************************************************
public static String collectPhone(String messageIn) {
    String expression = "^\\(?(\\d{3})\\)?[- ]?(\\d{3})[- ]?(\\d{4})$";
    Pattern pattern = Pattern.compile(expression, Pattern.CASE_INSENSITIVE);

    Scanner input = new Scanner(System.in);
    String strOut = "";
    boolean valid = true;

    System.out.println(messageIn);
    while (valid) {
        try {
            strOut = input.nextLine();
            CharSequence phoneChk = strOut;
            Matcher matcher = pattern.matcher(phoneChk);
            if (!matcher.matches()) {
                throw new Exception();
            }
            valid = false;
        } catch (Exception e) {
            System.out.printf("Please try again with a valid phone "
                    + "number\n");
        } //end catch
    } //end while

    return strOut;

}//end collectPhone method

//*************************************************************************
public static String collectSsn(String messageIn) {
    String expression = "^\\d{3}[- ]?\\d{2}[- ]?\\d{4}$";
    Pattern pattern = Pattern.compile(expression, Pattern.CASE_INSENSITIVE);

    Scanner input = new Scanner(System.in);
    String strOut = "";
    boolean valid = true;

    System.out.println(messageIn);
    while (valid) {
        try {
            strOut = input.nextLine();
            CharSequence ssnChk = strOut;
            Matcher matcher = pattern.matcher(ssnChk);
            if (!matcher.matches()) {
                throw new Exception();
            }
            valid = false;
        } catch (Exception e) {
            System.out.printf("Please try again with a valid social security "
                    + "number\n");
        } //end catch
    } //end while

    return strOut;

}//end collectSsn 
} //end Validate Class

导入java.nio.file.*； 导入java.io.*； 导入静态java.nio.file.StandardOpenOption.*； 导入java.nio.file.attribute.BasicFileAttributes； 导入java.nio.file.attribute.FileTime； 导入java.util.InputMismatchException； 导入java.util.Scanner； 导入java.util.regex.Matcher； 导入java.util.regex.Pattern； 公共阶级下层和上层{ 公共静态void main（字符串[]args）{ 路径文件1= get（“C:/temp/lowercassman.txt”）； 路径文件2= get（“C:/temp/upperclassman.txt”）； 字符串s=“”； 字符串分隔符=“，”； int-id； 字符串名； 双重信用； 最终int QUIT=999； 试一试{ OutputStream输出=新的BufferedOutputStream（Files.newOutputStream（file1））； BufferedWriter writerUpper=新的BufferedWriter（新的OutputStreamWriter（输出））； OutputStream output2=新的BufferedOutputStream（Files.newOutputStream（file2））； BufferedWriter writerLower=新的BufferedWriter（新的OutputStreamWriter（output2））； while（true）{ id=Validate.collectInt（“输入学生id号或”+退出 +“退出>>”； 如果（id==退出）{ 打破 } name=Validate.collectString（2，“输入学生姓名” +id+“>>”； creditsEarned=Validate.collectWage（“输入学分>>”； s=id+delimiter+name+delimiter+creditsEarned； 如果（creditsEarned>60 writerUpper.write）{ System.out.println（“学生是低年级学生”）； else（writerLower.write）{ System.out.println（“学生是高年级学生”）； } } writeUpper.write（s，0，s.length（））； r、 换行符（）； }//结束时 writer.close（）； writer2.close（）； }捕获（例外e）{ System.out.println（“消息：+e”）； } } } // ************************************************************************** 类验证{ 公共静态整型集合整型（字符串messageIn）{ 扫描仪输入=新扫描仪（System.in）； int intOut=0； 布尔有效=真； System.out.println（messageIn）； while（有效）{ 试一试{ intOut=input.nextInt（）； 有效=错误； }捕获（输入不匹配异常ie）{ input.nextLine（）； System.out.println（“必须输入整数”）； }//端盖 }//结束时 返回输入； }//结束收集方法 //************************************************************************* 公共静态字符串集合字符串（int strLen，String messageIn）{ 扫描仪输入=新扫描仪（System.in）； 字符串strOut=“”； 布尔有效=真； System.out.println（messageIn）； while（有效）{ 试一试{ strOut=input.nextLine（）； if（strOut.length（）BufferedWriter writerUpper = new BufferedWriter(new OutputStreamWriter(output));

writer.close();

r.newLine();

if(condition) 
{
    //do something
}
else
{
    //do something else
}

if (creditsEarned>60 writerUpper.write){
          System.out.println("Student is a Lowerclassman");

        else (writerLower.write){
System.out.println("Student is an Upperclassman");
}
}

if (creditsEarned> 60){
    writerUpper.write(s, 0, s.length());
    writerUpper.newLine();
}
else
{
    writerLower.write(s, 0, s.length());
    writerLower.newLine();
}

writerLower.close();
writerUppder.close();