import java.io.*;

public class OutputExpression {
    //File fWriter=new File("test.txt");;
    File fWriter;
    //Writer out=new FileWriter(fWriter);
    //BufferedWriter buffWrite=new BufferedWriter(out);
    Writer out;
    BufferedWriter buffWrite;

    OutputExpression(File file) throws IOException {//构造函数指定输出文件
        fWriter = file;
        out = new FileWriter(fWriter);
        buffWrite = new BufferedWriter(out);
    }

    public void expOutput(String str1) {
        try {

            buffWrite.write(str1);//写入计算机计算的表达式
            buffWrite.newLine();//换行
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public void outClose() {
        try {
            buffWrite.close();
            out.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}