public class Reader {
public static void main(String[] args) throws IOException, ParseException {
BufferedReader reader;
String animalName="cat";
String animal = null;
try {
reader = new BufferedReader(new InputStreamReader(
new FileInputStream("C:/dila.txt")));
Map<String, Integer> result = new LinkedHashMap<String, Integer>();
Map<String, Integer> result2 = new LinkedHashMap<String, Integer>();
while (reader.ready()) {
String line = reader.readLine();
/split a line with spaces/
String[] values = line.split(",");
String key = null;
if(values[1].compareTo(animalName)==0){
key = values[0];
animal=""+values[1].compareTo(animalName);
int sum = 0;
int count = 0;
/get a last counter and sum/
if (result.containsKey(key)) {
sum = result.get(key);
count = result2.get(key);
} else{
}
/increment sum a count and save in the map with key/
result.put(key, sum + Integer.parseInt(values[2]));
result2.put(key, count + 1);
}
}
/interate and print new output/
for (String key : result.keySet()) {
Integer sum = result.get(key);
Integer count = result2.get(key);
System.out.println(key +" "+animalName+ " " + sum + "\t" + count);
}
reader.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
我从","中分离出大量数据.所以我想读线和拆分.我已经做到了.但我的要求是上面显示的结果.
以下是执行此操作的代码.我正在接受google-guava库的帮助,因为它可以帮助我编写更少的代码;-).如果你只是想在普通的java中那么你也可以修改代码,如果逻辑需要一些调整然后看看processLine(...)方法,那就是改变的地方
好吧,我看到的唯一缺失的代码是按排序顺序打印不属于输入文件的日期的空数据.这很简单,留给你.以下是提示:将日期递增1并循环到月末
我已经运行了您的示例文件并打印了以下摘要
11/3/2010 cat 89 3
11/3/2010 dog 3 1
11/2/2010 dog 4 1
11/2/2010 cat 20 3
import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import java.util.Map;
import com.google.common.base.CharMatcher;
import com.google.common.base.Charsets;
import com.google.common.base.Joiner;
import com.google.common.base.Splitter;
import com.google.common.collect.Maps;
import com.google.common.io.Files;
import com.google.common.io.LineProcessor;
public class AnimalSummaryBuilder
{
private static final Splitter SPLITTER = Splitter.on(CharMatcher.anyOf(","));
private static final Joiner JOINER = Joiner.on("\t");
@SuppressWarnings("unchecked")
public static void main(final String[] args) throws Exception
{
@SuppressWarnings("rawtypes")
Map<Animal, Summary> result = Files.readLines(new File("c:/1.txt"), Charsets.ISO_8859_1, new LineProcessor() {
private final Map<Animal, Summary> result = Maps.newHashMap();
public Object getResult()
{
return result;
}
public boolean processLine(final String line) throws IOException
{
Iterator<String> columns = SPLITTER.split(line).iterator();
String date = columns.next();
String name = columns.next();
int value = Integer.valueOf(columns.next()).intValue();
Animal currentRow = new Animal(date, name);
if (result.containsKey(currentRow))
{
Summary summary = result.get(currentRow);
summary.increaseCount();
summary.addToTotal(value);
}
else
{
Summary initialSummary = new Summary();
initialSummary.setCount(1);
initialSummary.setTotal(value);
result.put(currentRow, initialSummary);
}
return true;
}
});
for (Map.Entry<Animal, Summary> entry : result.entrySet())
{
Animal animal = entry.getKey();
Summary summary = entry.getValue();
System.out.println(JOINER.join(animal.date, animal.name, summary.total, summary.count));
}
}
final static class Animal
{
String date;
String name;
public Animal(final String date, final String n)
{
this.date = date;
this.name = n;
}
@Override
public int hashCode()
{
final int prime = 31;
int result = 1;
result = prime * result + ((date == null) ? 0 : date.hashCode());
result = prime * result + ((name == null) ? 0 : name.hashCode());
return result;
}
@Override
public boolean equals(Object obj)
{
if (this == obj)
{
return true;
}
if (obj == null)
{
return false;
}
if (!(obj instanceof Animal))
{
return false;
}
Animal other = (Animal) obj;
if (date == null)
{
if (other.date != null)
{
return false;
}
}
else if (!date.equals(other.date))
{
return false;
}
if (name == null)
{
if (other.name != null)
{
return false;
}
}
else if (!name.equals(other.name))
{
return false;
}
return true;
}
}
final static class Summary
{
private int total;
private int count;
void setTotal(int value)
{
total = value;
}
void setCount(int i)
{
count = i;
}
void increaseCount()
{
count++;
}
void addToTotal(int valueToAdd)
{
total += valueToAdd;
}
}
}
| 归档时间： |
|
| 查看次数： |
361 次 |
| 最近记录： |