chap5课堂练习.rar

package cbsc.cha3; import java.io.*; import java.util.Iterator; import java.util.List; import java.util.Random; import java.util.ArrayList; import java.util.Scanner; public class Exercise_3_2_cha7 implements Serializable{ private static final long serialVersionUID = -1622536020144679558L; class Answers implements Serializable{ private static final long serialVersionUID = -7833709422448085208L; String content; boolean correct; public Answers(){content = ""; correct = false;} public Answers(String ans, boolean cr){ content = ans; correct = cr; } } private ArrayList<BinaryOperation_3_2> operationList = new ArrayList<BinaryOperation_3_2>(); // private List <String> answers = new ArrayList<>(); //第7章增加：用户填写的所有题目的答案 private List <Answers> answers = new ArrayList<>(); //第7章增加：用户填写的所有题目的答案 private int current=0; // only used for iterator private ExerciseType currentType; //第7章新添加题目类型，为保存用 public ExerciseType getCurrentType() { return currentType; } public void setAnswer(int index, String ans){ BinaryOperation_3_2 op; op = operationList.get(index); String result = String.valueOf(op.getResult()); String tans = ans.trim(); answers.set(index, new Answers(tans,result.equals(tans))); } public String getAnswer(int index){ return answers.get(index).content; } public void clearAnswers(){ for(int i=0; i<answers.size(); i++) answers.set(i,new Answers("",false)); } public int Correct(){ int count=0; for(int i=0; i<answers.size(); i++){ if(answers.get(i).correct) count++; } return count; } private void setCurrentType(ExerciseType type) { this.currentType = type; } public boolean getJudgement(int index){ return answers.get(index).correct; } private BinaryOperation_3_2 generateOperation(){ Random random = new Random(); int opValue = random.nextInt(2); if (opValue == 1){ return new AdditionOperation(); } return new SubstractOperation(); } public void saveObject(String filename) throws ExerciseIOException{ //串行化存储对象 try { FileOutputStream fos = new FileOutputStream(filename); ObjectOutputStream oos = new ObjectOutputStream(fos); oos.writeObject(this); oos.close(); fos.close(); } catch (Exception e) { e.printStackTrace(); throw new ExerciseIOException("存储对象失败"); } } public static Exercise_3_2_cha7 loadObject(String filename) throws ExerciseIOException{ //串行化载入对象 Exercise_3_2_cha7 exercise = null; try{ FileInputStream fis = new FileInputStream(filename); ObjectInputStream ois = new ObjectInputStream(fis); exercise = (Exercise_3_2_cha7)ois.readObject(); ois.close(); fis.close(); }catch(Exception e){ throw new ExerciseIOException("载入对象失败"); } return exercise; } //以下函数为第7章新添加，不改变原类型，但是可以改变数量，产生一批新的题目 public void generateWithFormerType(int operationCount){ switch(currentType){ case ADD_AND_SUB: this.generateBinaryExercise(operationCount); break; case ADD_ONLY: this.generateAdditionExercise(operationCount); break; case SUB_ONLY: this.generateSubstractExercise(operationCount); break; } } public void generateAdditionExercise( int operationCount){ BinaryOperation_3_2 anOperation; /* * 根据第7章内容添加部分代码 */ setCurrentType(ExerciseType.ADD_ONLY); //设置题目类型 operationList.clear(); //先清空再生成 answers.clear(); while (operationCount > 0 ){ do {anOperation = new AdditionOperation(); }while (operationList.contains(anOperation)); operationList.add(anOperation); answers.add(new Answers("",false)); //System.out.println("count="+ operationList.size()); operationCount--; } } public void generateBinaryExercise(int operationCount){ BinaryOperation_3_2 anOperation; /* * 根据第7章内容添加部分代码 */ setCurrentType(ExerciseType.ADD_AND_SUB); //设置题目类型 operationList.clear(); //先清空再生成 answers.clear(); while (operationCount > 0 ){ do{anOperation = generateOperation(); }while (operationList.contains(anOperation)); operationList.add(anOperation); answers.add(new Answers("",false)); operationCount--; } } public void generateSubstractExercise(int operationCount){ BinaryOperation_3_2 anOperation; /* * 根据第7章内容添加部分代码 */ setCurrentType(ExerciseType.SUB_ONLY); //设置题目类型 operationList.clear(); //先清空再生成 answers.clear(); while (operationCount > 0 ){ do{anOperation = new SubstractOperation(); }while (operationList.contains(anOperation)); operationList.add(anOperation); answers.add(new Answers("",false)); operationCount--; } } // --- 2015-8-4: begin public void add(BinaryOperation_3_2 anOperation){ operationList.add(anOperation); } public boolean contains(BinaryOperation_3_2 anOperation){ return operationList.contains(anOperation); } public int length(){ return operationList.size(); } // write Exercise in a file, each Operation as "3+5" public void writeExercise(){ File wfile = new File("eq2.txt"); try{ Writer out = new FileWriter(wfile, true); for (BinaryOperation_3_2 op: operationList){ out.write(op.toString()+","); } out.flush(); out.close(); } catch(IOException e){ System.out.println("ERROR: "+e); } } public void writeCSVExercise(File aFile){ try{ Writer out = new FileWriter(aFile, true); for (BinaryOperation_3_2 op: operationList){ out.write(op.toString()+","); } out.flush(); out.close(); } catch(IOException e){ System.out.println("ERROR: "+e); } } // read in a file each as "3+5", and convert to Operation， add in Exercise public Exercise_3_2_cha7 readCSVExercise(){ Exercise_3_2_cha7 exercise = new Exercise_3_2_cha7(); String eqString; BinaryOperation_3_2 op; Scanner sc = null; File rfile = new File("eq2.txt"); try{ sc = new Scanner(rfile); sc.useDelimiter(",\\n"); while(sc.hasNext()){ eqString = sc.next(); op = new AdditionOperation(); op.unsafeConstructor(eqString); exercise.add(op); } } catch(IOException e){ System.out.println("ERROR: "+e); } return exercise; } public Exercise_3_2_cha7 readCSVExercise(File aFile){ Exercise_3_2_cha7 exercise = new Exercise_3_2_cha7(); String eqString; BinaryOperation_3_2 op; try{ Scanner sc = new Scanner(aFile); sc.useDelimiter(","); while(sc.hasNext()){ // 处理任意的\t，\f， \n等 eqString = sc.next().replaceAll("\\s", ""); op = new AdditionOperation(); op.unsafeConstructor(eqString); exercise.add(op); } sc.close(); } catch(IOException e){ System.out.println("ERROR: "+e); } return exercise; } // ---- 2015-8-4: ----- end // 下面两个方法用于实现遍历数据 public boolean hasNext(){ // 若有元素返回true，否则返回false， return current <= operationList.size()-1; } public BinaryOperation_3_2 next(){ // 若有元素返回当前元素，移动到一个 return operationList.get(current++); } public void printCurrent(){ System.out.println("current="+current); } //根据第7章的需求新添加的一种获取元素的方法 public BinaryOperation_3_2 getOperation(int index){ if(index < operationList.size()) return operationList.get(index); else return null; } // for test public void all(){ for (BinaryOperation_3_2 op:operationList){ System.out.println(op.asString()); } } // for test public void writeResults(File aFile){ try{ Writer out = new FileWriter(aFile, true); for (BinaryOperation_3_2 op: operationList){ out.write(op.getResul