两个10G的csv文件（t1.csv, t2.csv），两个csv文件里面表头为：id，name，grade
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| id： String类型
name： String类型
grade： String类型
|
服务器内存只有1G，找出grade不为空，且grade数字大于90的数据，输出到当前目录下t3.csv文件中。
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| import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
@AllArgsConstructor
public class Reader extends Thread {
private final String path;
private final BufferedWriter writer;
public void run() {
File inputFile = new File(path);
try {
BufferedReader reader = new BufferedReader(new FileReader(inputFile));
reader.readLine();
while (reader.ready()) {
String line = reader.readLine();
String[] splitline = line.split(",");
double temp = Double.parseDouble(splitline[2]);
if (temp > 90) {
writer.write(line);
writer.newLine();
writer.flush();
}
}
reader.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
|
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| import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
public class DataFilter {
public static void main(String[] args) {
File outputFile = new File("C:\\Users\\Yoon\\Desktop\\t3.csv");
try {
BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(outputFile));
Thread t1 = new Reader("C:\\Users\\Yoon\\Desktop\\t1.csv", bufferedWriter);
Thread t2 = new Reader("C:\\Users\\Yoon\\Desktop\\t2.csv", bufferedWriter);
t1.start();
t2.start();
} catch (Exception e) {
e.printStackTrace();
}
}
}
|