如何從文本文件中將文本轉換爲對象的字段

Question

好吧，我得到一個文本文件，對它進行標記，然後嘗試將其寫入另一個文件。

我有一類叫做當然它有4個參數：名稱，層次，代碼，一年

我劃分了文本文件的每一行到另一條線路

@Edit：應該提到這較早，但我已存儲在一個文本文件

public void readFromFile() throws IOException 
{ 
    int index = 0; 
    int j = -1; 
    int spaceCount = 0; 
    courseNumber++; 

    setCourseFields(); 

    BufferedReader inputFile = new BufferedReader(new FileReader(INPUT_FILE)); 
    PrintWriter outputFile = new PrintWriter(new FileWriter(OUTPUT_FILE)); 

    String lineOfText = inputFile.readLine(); 

    while (lineOfText != null)   
    { 
     outputFile.println(lineOfText); 
     lineOfText = inputFile.readLine(); 

     for (char c : lineOfText.toCharArray()) 
     { 
      if (c == ' ') 
      { 
       spaceCount++; 
      } 
     } 

     if(spaceCount == 1) 
     { 
      delimiter = DELIMITER_SPACE; 

     } 
     else if(spaceCount == 2) 
     { 
      delimiter = DELIMITER_TAB; 
     } 

     System.out.println("Course" + courseNumber + "\n"); 

     // for each token in the string 
     while ((j = lineOfText.indexOf(delimiter, (index = ++j))) != -1) 
     { 
      System.out.println(courseField[k] + ": " + lineOfText.substring(index, j)); 
      counter++; 
      k++; 

     } 

     // extract the last token 
     if (index > 0) 
     { 
      System.out.println("Year: " + lineOfText.substring(index)); 
      ++courseNumber; 
     } 

     if(k == 3) 
     { 
      k = k - k; 
      index = 0; 
     } 

     delayDisplay(); 

    } // while(lineOfText != null) 

    inputFile.close(); 
    outputFile.close(); 
} 

3000門課程然後我會得到這樣的事情

Course1 

Name: Computer Engineering Technology 
Level: IB 
Code: TEJ4M 
Year: 2017 


Course2 

Name: Communications Technology 
Level: Special Education 
Code: TGJ2O 
Year: 2002 

每門課程都是獨一無二的，我需要幫助，以便我可以將上述每個字符串分配給一個變量。

每門課程有4個實例字段+一個唯一的序列號（課程編號）

的4個領域是：

String name; 
char level; 
String code; 
int academicYear; 

我要讓課程出每個4線的

這是我的課程班

public class Course extends Object implements Serializable 
{ 
// class constants 
public static final String DEFAULT_CODE = "AAA10"; 
public static final char DEFAULT_LEVEL = 'X'; 
public static final String DEFAULT_NAME = "unassigned"; 
public static final int DEFAULT_YEAR = 1900; 

private static final char ACADEMIC_LEVEL = '1'; 
private static final char ENGLISH_LANGUAGE_LEARNERS_LEVEL = '9'; 
private static final int ERROR_CODE = -1; 
private static final char IB_LEVEL = '7'; 
private static final int MAXIMUM_YEAR = 2014; 
private static final int MINIMUM_YEAR = 1900; 
private static final char SPECIAL_EDUCATION_LEVEL = '8'; 

// instance variables 
private int academicYear; 
private String code; 
private static int counter = 0; 
private char level; 
private String name; 
private int serialNumber; 

/** 
* Constructs a course with default characteristics. 
*/ 
public Course() 
{ 
    this.academicYear = DEFAULT_YEAR; 
    this.code = DEFAULT_CODE; 
    this.level = DEFAULT_LEVEL; 
    this.name = DEFAULT_NAME;   
    serialNumber = ++counter; 
} // end of constructor Course() 

/** 
* Constructs a course with the specified characteristics. 
* 
* @param name - the Ministry-assigned name of this course; 
*  ex: Introduction to Computer Science 
* @param code - the Ministry-assigned code of this course; ex: ICS3U 
* @param level - one of the enumerated levels ex: '7', '1', '9', '8' 
* @param academicYear - a 4-digit year of the Gregorian calendar 
*  set between a minimum and maximum year 
*/ 
public Course(String name, String code, char level, int academicYear) 
{ 
    if(name == null) 
    { 
     this.name = DEFAULT_NAME; 
    } 
    else 
    { 
     this.name = name; 
    } // end of if(name == null) 
    if(code == null) 
    { 
     this.code = DEFAULT_CODE; 
    } 
    else 
    { 
     this.code = code; 
    } // end of if(code == null) 
    if (level == IB_LEVEL || level == ACADEMIC_LEVEL 
    || level == ENGLISH_LANGUAGE_LEARNERS_LEVEL 
    || level == SPECIAL_EDUCATION_LEVEL) 
    { 
     this.level = level; 
    } 
    else 
    { 
     this.level = DEFAULT_LEVEL; 
    } // end of if (level == IB_LEVEL || level == ACADEMIC_LEVEL || level == 
    ENGLISH_LANGUAGE_LEARNERS_LEVEL || level == SPECIAL_EDUCATION_LEVEL) 

    if (academicYear >= MINIMUM_YEAR && academicYear <= MAXIMUM_YEAR) 
    { 
     this.academicYear = academicYear; 
    } 
    else 
    { 
     this.academicYear = DEFAULT_YEAR; 
    } // end of (academicYear >= MINIMUM_YEAR && academicYear <= MAXIMUM_YEAR) 
    serialNumber = ++counter; 
} // end of constructor Course(String name, String code, char level, int academicYear) 

/* Comparison methods*/ 
/** 
* Indicates whether another object has a state identical to this object’s state. 
* 
* @param otherCourse - the object whose state is compared to this object’s 
* 
* @return true if the other object has an identical state; otherwise false 
*/ 
public boolean equals(Object otherCourse) 
{   
    if(otherCourse == null) return false; 
    if (this.getClass() != otherCourse.getClass()) return false; 
    if (this == otherCourse) return true; 

    // Typecasting Object otherCourse into a Course to compare objects' states 
    Course course1 = (Course) otherCourse; 

    if(serialNumber != course1.getSerialNumber()) return false; 
    if(academicYear != course1.getYear()) return false; 
    if(level != course1.getLevel()) return false; 
    if(code != course1.getCode()) return false; 
    if(name != course1.getName()) return false; 

    // needed to satisfy the compiler 
    return true; 

} // end of method boolean equals(Object course) 

/** 
* Indicates whether another object has a state identical to this object’s state, 
* ignoring each object's unique serial number. 
* 
* @param otherCourse - the object whose state is compared to this object’s 
* 
* @return true if the other object has an identical state; otherwise false 
*/ 
public boolean equalsIgnoreSerial(Object otherObject) 
{ 
    if(otherObject == null) return false; 
    if (this.getClass() != otherObject.getClass()) return false; 
    boolean courseEquals; 
    Course anotherCourse = (Course) otherObject;  
    // Ignore unique serial number of each course 
    if(this.serialNumber == anotherCourse.getSerialNumber()) return false; 
    if(this.academicYear != anotherCourse.getYear()) return false; 
    else courseEquals = true; 
    if(this.level != anotherCourse.getLevel()) return false; 
    else courseEquals = true; 
    if(this.code != anotherCourse.getCode()) return false; 
    else courseEquals = true; 
    if(this.name != anotherCourse.getName()) return false; 
    else courseEquals = true; 

    return courseEquals; 
} // end of method boolean equalsIgnoreSerial(Object course 

/** 
* Compares this Course to another. 
* 
* @return a negative value, if this course should come before the other course; 
* 0, if this course and the other course have equal states; 
* a positive value if this course should come after the other course 
*/ 
public int compareTo(Course otherCourse) 
{ 
    int before = -1; 
    int after = 1; 
    int equals = 0; 
    int resultCode = code.compareTo(otherCourse.getCode()); 
    int resultName = name.compareTo(otherCourse.getName()); 

    if(otherCourse == null) return -1; 
    if(this.equals(otherCourse)) return equals; 

    if(serialNumber < otherCourse.getSerialNumber()) return before; 
    if(serialNumber > otherCourse.getSerialNumber()) return after; 

    if(academicYear < otherCourse.getYear()) return before; 
    if(academicYear > otherCourse.getYear()) return after; 

    if(!(sortLevel(level) == -1 || sortLevel(otherCourse.getLevel()) == -1)) 
    { 
     if(sortLevel(level) < sortLevel(otherCourse.getLevel())) return before; 
     if(sortLevel(level) > sortLevel(otherCourse.getLevel())) return after; 
    } // end of if(!(sortLevel(level) == -1 || sortLevel(otherCourse.getLevel()) == 
        -1)) 

    if(code.compareTo(otherCourse.getCode()) != 0) return resultCode; 

    if(name.compareTo(otherCourse.getName()) != 0) return resultName; 

    // neccessary to satisfy the compiler 
    return 5; 

} // end of public int compareTo(Course otherCourse) 

/* utility methods*/ 
public static int sortLevel(char level) 
{ 
    /************************************* 
    final char[] LEVEL = {'7', '1', '9', '8'}; 
    for (int index = 0; index < LEVEL.length; index++) 
    { 
    if(LEVEL[index] == level) return index; 
    if(LEVEL[index] != level) return ERROR_IO_EXCEPTION; 
    } // end of for (int index = 0; index < LEVEL.length; index++) 

    // error code for not found, should not be reached 
    return -1; 
    ****************************************/ //code taken from in class discussion 

    final char[] LEVEL = {'7', '1', '9', '8'}; 
    for (int index = 0; index < LEVEL.length; index++) 
    { 
     if(LEVEL[index] == level) return index; 
     if(LEVEL[index] != level) return -1; 
    } // end of for (int index = 0; index < LEVEL.length; index++) 

    // error code for not found, should not be reached 
    return ERROR_CODE; 
} // end of public static int sortLevel(char level) 

/* accessors*/ 

/** 
* Returns the code of this course. 
* 
* @returns Returns the code of this course 
*/ 
public String getCode() 
{ 
    return code; 
} // end of method getCode() 

/** 
* Returns the level of this course. 
* 
* @return the level of this course 
*/ 
public char getLevel() 
{ 
    return level; 
} // end of method getLevel() 

/** 
* Returns the name of this course. 
* 
* @return the name of this course. 
*/ 
public String getName() 
{ 
    return name; 
} // end of method getName() 

/** 
* Returns the unique serial number of this course. 
* 
* @return the unique serial number of this course. 
*/ 
public int getSerialNumber() 
{ 
    return serialNumber; 
} // end of method getSerialNumber() 

/** 
* Returns the academic year of this course. 
* 
* @return the 4-digit academic year of this course 
*/ 
public int getYear() 
{ 
    return academicYear; 
} // end of method getYear() 

/* mutators */ 
/** 
* Sets the code of this course. 
* 
* @param newCode - the new code of this course. 
*/ 
public void setCode(String newCode) 
{ 
    if (newCode == null) return; 
    this.code = newCode; 
} // end of method setCode(String newCode) 

/** 
* Sets the level of this course. 
* 
* @param newLevel - one of the enumerated levels 
*/ 
public void setLevel(char newLevel) 
{ 
    if(newLevel == IB_LEVEL || newLevel == ACADEMIC_LEVEL || newLevel == 
    ENGLISH_LANGUAGE_LEARNERS_LEVEL || newLevel == SPECIAL_EDUCATION_LEVEL) 
    { 
     level = newLevel; 
    } 
    else 
    { 
     level = DEFAULT_LEVEL; 
    } // end of if(newLevel == IB_LEVEL || newLevel == ACADEMIC_LEVEL || newLevel == 
     ENGLISH_LANGUAGE_LEARNERS_LEVEL || newLevel == SPECIAL_EDUCATION_LEVEL) 
} // end of method setLevel(char newLevel) 

/** 
* Sets the name of this course. 
* 
* @param newName - the new name of this course 
*/ 
public void setName(String newName) 
{ 
    if (newName == null) return; 
    this.name = newName; 
} // end of method setName(String newName) 

/** 
* Sets the academic year of this course. 
* 
* @param newYear - the new 4-digit academic year of this course 
*/ 
public void setYear(int newYear) 
{ 
    if (newYear >= MINIMUM_YEAR && newYear <= MAXIMUM_YEAR) 
    { 
     this.academicYear = newYear; 
    } 
    else 
    { 
     academicYear = DEFAULT_YEAR; 
    } // end of if (newYear >= MINIMUM_YEAR && newYear <= MAXIMUM_YEAR) 
} // end of method setYear(int newYear) 

/** 
* Returns a string representation of this course. 
* 
* @override toString in class Object 
* 
* @return a string representation of this course. 
*/ 
public String toString() 
{  
    return 
    this.getClass().getName() 
    +"[" 
    + "Serial Number: " + serialNumber 
    + ", academic year: " + academicYear 
    + ", level: " + level 
    + ", code: " + code 
    + ", name: " + name 
    +"]"; 
} // end of String toString() 

而且，我需要幫助轉換字符串成水平和成學年一個int一個字符，任何想法

這裏是我CourseUtility類，這還沒有結束，

public class CourseUtility 
{ 
// class constants 
private static final String INPUT_FILE = "courses.text"; 
private static final String OUTPUT_FILE = "CoursesTokenized.text"; 
private static int counter = 0; 
private static int courseNumber = 0; 
private static int k = 0; 
private static final String DELIMITER_SPACE = " "; 
private static final String DELIMITER_TAB = "\t"; 
String delimiter = DELIMITER_TAB; 
private static final String DEFAULT_LEVEL = "X"; 

String name = ""; 
String code = ""; 
String year = ""; 
String level = ""; 
String lineOfText; 
private static String[] courseField = new String[5]; 

/** 
* Constructor for objects of class CourseUtility 
*/ 
public CourseUtility() throws IOException 
{ 

} 

public void readFromFile() throws IOException 
{ 
    int index = 0; 
    int j = -1; 
    int spaceCount = 0; 
    courseNumber++; 

    setCourseFields(); 

    BufferedReader inputFile = new BufferedReader(new FileReader(INPUT_FILE)); 
    PrintWriter outputFile = new PrintWriter(new FileWriter(OUTPUT_FILE)); 

    String lineOfText = inputFile.readLine(); 
    while (lineOfText != null)   
    { 
     for (char c : lineOfText.toCharArray()) 
     { 
      if (c == ' ') 
      { 
       spaceCount++; 
      } 
     } 

     if(spaceCount == 1) 
     { 
      delimiter = DELIMITER_SPACE; 

     } 
     else if(spaceCount == 2) 
     { 
      delimiter = DELIMITER_TAB; 
     } 

     System.out.println("Course" + courseNumber); 

     // for each token in the string 
     while ((j = lineOfText.indexOf(delimiter, (index = ++j))) != -1) 
     {     
      System.out.println(courseField[k] + ": " + lineOfText.substring(index, j)); 
      System.out.println(""); 
      outputFile.println(lineOfText.substring(index, j)); 
      counter++; 
      k++; 

     } 

     // extract the last token 
     if (index > 0) 
     { 
      System.out.println("Year: " + lineOfText.substring(index)); 
      outputFile.println(lineOfText.substring(index)); 
      ++courseNumber; 
     } 
     // for each token in the string 
     //    Course c = new Course(hm.get("Name"), hm.get("Code"), 
hm.get("Level"), Integer.parseInt(hm.get("Year"))); 
     //    System.out.println(c); 

     if(k == 3) 
     { 
      k = k - k; 
      index = 0; 
     } 

     delayDisplay(); 
     lineOfText = inputFile.readLine(); 

    } // while(lineOfText != null) 

    inputFile.close(); 
    outputFile.close(); 
} 

public CourseUtility(String name, String code, String level, String year) 
{ 
    if(name == null) 
    { 
     this.name = Course.DEFAULT_NAME; 
    } 
    else 
    { 
     this.name = name; 
    } // end of if(name == null) 
    if(code == null) 
    { 
     this.code = Course.DEFAULT_CODE; 
    } 
    else 
    { 
     this.code = code; 
    } // end of if(code == null) 
    if(level == null) 
    { 
     this.level = DEFAULT_LEVEL; 
    } 
    else 
    { 
     this.level = level; 
    } // end of if(level == null) 
    if(year == null) 
    { 
     this.year = null;; 
    } 
    else 
    { 
     this.year = year; 
    } // end of if(year == null) 

} 

private void delayDisplay() 
{ 
    try 
    { 
     Thread.sleep(1000); 
    } catch(InterruptedException ex) 
    { 
     Thread.currentThread().interrupt(); 
    } // end of try 
} // end of method void delayDisplay() 

private void convertLevel(String courseLevel) 
{   
    level = DEFAULT_LEVEL; 
    if(level == "IB") level = "7"; 
    if(level == "Academic")level = "1"; 
    if(level == "Applied") level = "1"; 
    if(level == "ELL") level = "9"; 
    if(level == "Special Education") level = "8"; 
} // end of method convertLevel(String courseLevel) 

public void deleteCourse() 
{ 

private void setCourseFields() 
{ 
    courseField[0] = "Name"; 
    courseField[1] = "Level"; 
    courseField[2] = "Code"; 
    courseField[3] = "Year"; 
} // end of method setCourseFields() 

} 

Answer 1

我想我看到你的問題。您解析字段，但不保存它們。有一件事你可以做的是保存領域，一旦你有他們。將它們存儲在HashMap中，其中鍵是該字段的名稱。然後使用您的HashMap檢索字段並調用構造函數：

// for each token in the string 
HashMap<String,String> hm = new HashMap<String,String>(); //NEW 
while ((j = lineOfText.indexOf(delimiter, (index = ++j))) != -1) 
{ 
    hm.put(courseField[k], lineOfText.substring(index, j)); //NEW 
    System.out.println(courseField[k] + ": " + lineOfText.substring(index, j)); 
    counter++; 
    k++; 

} 

// extract the last token 
if (index > 0) 
{ 
    System.out.println("Year: " + lineOfText.substring(index)); 
    hm.put("Year", lineOfText.substring(index)); //NEW 
    ++courseNumber; 
} 

//translate level string to a character 
char lvl; 
String sLevel = hm.get("Level"); 
if (sLevel.equals("IB")) 
    lvl = '7'; 
else if (sLevel.equals("Special Education")) 
    lvl = '8'; 
else if (sLevel.equals("Academic")) 
    lvl = '8'; 
else if (sLevel.equals("English Language Learners")) 
    lvl = '1'; 
else 
    lvl = ' '; /* unknown level */ 

//create the Course object 
Course c = new Course(hm.get("Name"), hm.get("Code"), lvl , Integer.parseInt(hm.get("Year")));