有些时候我们需要写批处理任务，但是我们需要监控处理的进度，这个时候我们需要写一个计数器在统计，获取还需要好看一些。工具类代码没有第三方依赖，拷贝了网上其他出处的代码加以修改，因为源代码只能处理100条标准的数据，该进度条，不管你有多少条数据都可以正确显示如下图:
使用方式也是很简单:
public static void main(String[] args) throws Exception {
long dataLength = 1330;
ProgressBar bar = ProgressBar.build(dataLength);
for (int i = 0; i < dataLength; i++) {
Thread.sleep(10);
bar.process();
}
}
```
工具类代码如下:
```java
package tool.util;
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.text.NumberFormat;
import java.util.Objects;
/**
* 进度条工具
* <p>
* 这个进度条打印期间，其他控制台输出会影响最终结果
* 所以做成单线程，阻塞的打印
*
*/
public class ProgressBar {
/**
* 进度条长度
*/
private int BAR_LENGTH = 35;
/**
* 进度条缩放比例
*/
private BigDecimal resizeRate;
/**
* 总数据长度
*/
private long dataCount;
/**
* 当前进度
*/
private volatile long completeCount;
/**
* 完成进度在进度条中的数量
*/
private volatile int completeBarCount;
/**
* 完成进度百分比
*/
private volatile String completePercent;
/**
* 是否初始化
*/
private boolean hasInited = false;
/**
* 是否已经结束
*/
private boolean hasFinished = false;
/**
* 进度条title
*/
private String title;
private static final char processChar = '█';
private static final char waitChar = '─';
public static final long MILLIS_PER_SECOND = 1000;
public static final long MILLIS_PER_MINUTE = 60 * MILLIS_PER_SECOND;
public static final long MILLIS_PER_HOUR = 60 * MILLIS_PER_MINUTE;
public static final long MILLIS_PER_DAY = 24 * MILLIS_PER_HOUR;
private long startTime;
private long endTime;
private String content;
private ProgressBar() {
resizeRate = new BigDecimal(BAR_LENGTH).divide(new BigDecimal(100), 2, RoundingMode.HALF_UP);
}
private static ProgressBar build() {
return new ProgressBar();
}
public static ProgressBar build(long dataCount) {
return build(dataCount, 0, "Progress");
}
public static ProgressBar build(long dataCount, String title) {
return build(dataCount, 0, title);
}
public static ProgressBar build(long dataCount, long completeCount, String title) {
ProgressBar progressBar = build();
progressBar.dataCount = dataCount;
progressBar.completeCount = completeCount;
progressBar.title = title;
return progressBar;
}
private String generate(int num, char ch) {
if (num == 0) return "";
StringBuilder builder = new StringBuilder();
for (int i = 0; i < num; i++) {
builder.append(ch);
}
return builder.toString();
}
private String genProcess(int num) {
return generate(num, processChar);
}
private String genWaitProcess(int num) {
return generate(num, waitChar);
}
/**
* 清空进度条
*/
private void cleanProcessBar() {
if(Objects.nonNull(content)) {
// System.out.print(generate(content.length(), '\b'));
}
System.out.print('\r');
}
/**
* 进度+1
*/
public void process() {
checkStatus();
checkInit();
cleanProcessBar();
doProcess();
drawProgressBar();
checkFinish();
}
private void doProcess() {
completeCount++;
BigDecimal completeBarRate = getCompleteRate();
completeBarCount = genCompleteBarCount(completeBarRate);
completePercent = genCompletePercent(completeBarRate);
}
private int genCompleteBarCount(BigDecimal completeBarRate) {
BigDecimal completeBarCount = BigDecimal.ZERO;
if(completeCount > 0 && dataCount > 0) {
completeBarCount = completeBarRate
.multiply(new BigDecimal("100"))
.multiply(resizeRate);
}
return completeBarCount.intValue();
}
private String genCompletePercent(BigDecimal completeBarRate) {
NumberFormat percentInstance = NumberFormat.getPercentInstance();
percentInstance.setMaximumFractionDigits(2);
return percentInstance.format(completeBarRate);
}
private BigDecimal getCompleteRate() {
BigDecimal completeBarRate = BigDecimal.ZERO;
if(completeCount > 0 && dataCount > 0) {
completeBarRate = new BigDecimal(completeCount).divide(new BigDecimal(dataCount), 4, RoundingMode.HALF_UP);
}
return completeBarRate;
}
private String genDurationStr() {
long days = 0;
long hours = 0;
long minutes = 0;
long seconds = 0;
long milliseconds = System.currentTimeMillis() - startTime;
days = milliseconds / MILLIS_PER_DAY;
milliseconds = milliseconds - (days * MILLIS_PER_DAY);
hours = milliseconds / MILLIS_PER_HOUR;
milliseconds = milliseconds - (hours * MILLIS_PER_HOUR);
minutes = milliseconds / MILLIS_PER_MINUTE;
milliseconds = milliseconds - (minutes * MILLIS_PER_MINUTE);
seconds = milliseconds / MILLIS_PER_SECOND;
milliseconds = milliseconds - (seconds * MILLIS_PER_SECOND);
StringBuilder sb = new StringBuilder();
if(days > 0) {
sb.append(days).append('天');
}
if(hours > 0) {
sb.append(hours).append("小时");
}
if(minutes > 0) {
sb.append(minutes).append("分钟");
}
if(seconds > 0) {
sb.append(seconds).append('秒');
}
if(milliseconds > 0) {
sb.append(milliseconds).append("毫秒");
}
return sb.toString();
}
/**
* 绘制进度条
*/
private void drawProgressBar() {
checkStatus();
content = String.format(
"%s: %7s├%s%s┤%s",
title,
completePercent,
genProcess(completeBarCount),
genWaitProcess(BAR_LENGTH - completeBarCount),
genDurationStr()
);
System.out.print(content);
}
/**
* 检查进度条状态
* 已完成的进度条不可以继续执行
*/
private void checkStatus() {
if (hasFinished) throw new RuntimeException("进度条已经完成");
}
/**
* 检查是否已经初始化
*/
private void checkInit() {
if (!hasInited) init();
}
/**
* 检查是否已经完成
*/
private void checkFinish() {
if (hasFinished() && !hasFinished) finish();
}
/**
* 是否已经完成进度条
*
* @return
*/
private boolean hasFinished() {
return completeCount >= dataCount;
}
/**
* 初始化进度条
*/
private void init() {
hasInited = true;
startTime = System.currentTimeMillis();
}
/**
* 结束进度条，由 checkFinish()调用
*/
private void finish() {
System.out.println();
endTime = System.currentTimeMillis();
hasFinished = true;
}
}