User user1 = session.load(1);
User user2 = new User();
user2.setId(1);//此时ID和user1一样
user2.setUsername("fatkun");
session.update(user2);//这里会抛出错误

   /** The value is used for character storage. */
    private final char value[];
 
    /** The offset is the first index of the storage that is used. */
    private final int offset;
 
    /** The count is the number of characters in the String. */
    private final int count;

    public String concat(String str) {
	int otherLen = str.length();
	if (otherLen == 0) {
	    return this;
	}
	char buf[] = new char[count + otherLen];
	getChars(0, count, buf, 0);
	str.getChars(0, otherLen, buf, count);
	return new String(0, count + otherLen, buf);
    }

    public int indexOf(String str, int fromIndex) {
        return indexOf(value, offset, count,
                       str.value, str.offset, str.count, fromIndex);
    }
 
    //source源字符，sourceOffset源偏移，sourceCount源长度
    //target查找的字符 ...
    static int indexOf(char[] source, int sourceOffset, int sourceCount,
                       char[] target, int targetOffset, int targetCount,
                       int fromIndex) {
        //如果fromIndex比源字符还长(从0算起)，并且查找的字符长度为0，那就返回源字符的长度，否则返回-1
	if (fromIndex >= sourceCount) {
            return (targetCount == 0 ? sourceCount : -1);
	}
    	if (fromIndex < 0) {
    	    fromIndex = 0;
    	}
        //如果fromIndex比源字符短，查找的字符长度为0，直接返回fromIndex
	if (targetCount == 0) {
	    return fromIndex;
	}
 
        //先取出第一个字符
        char first  = target[targetOffset];
        int max = sourceOffset + (sourceCount - targetCount);
 
        //循环每一个字符
        for (int i = sourceOffset + fromIndex; i <= max; i++) {
            /* 直到找到第一个字符 */
            if (source[i] != first) {
                while (++i <= max && source[i] != first);
            }
 
            /* 找到第一个字符后，比较剩下的字符 */
            if (i <= max) {
                int j = i + 1;
                int end = j + targetCount - 1;
                for (int k = targetOffset + 1; j < end && source[j] ==
                         target[k]; j++, k++);
 
                if (j == end) {
                    /* 如果j能到end，那就说明找到整个字符串啦，返回偏移 */
                    return i - sourceOffset;
                }
            }
        }
        return -1;
    }

    public boolean equals(Object anObject) {
	if (this == anObject) {
	    return true;
	}
	if (anObject instanceof String) {
	    String anotherString = (String)anObject;
	    int n = count;
	    if (n == anotherString.count) {
		char v1[] = value;
		char v2[] = anotherString.value;
		int i = offset;
		int j = anotherString.offset;
		while (n-- != 0) {
		    if (v1[i++] != v2[j++])
			return false;
		}
		return true;
	    }
	}
	return false;
    }

    public String replace(CharSequence target, CharSequence replacement) {
        return Pattern.compile(target.toString(), Pattern.LITERAL).matcher(
            this).replaceAll(Matcher.quoteReplacement(replacement.toString()));
    }
 
    public String replaceAll(String regex, String replacement) {
	return Pattern.compile(regex).matcher(this).replaceAll(replacement);
    }

//图片标题
String title = "空调2002年市场占有率";
//设定数据源
DefaultPieDataset piedata = new DefaultPieDataset();
//第一个参数为名称，第二个参数是double数
piedata.setValue("联想", 27.3);
piedata.setValue("长城", 12.2);
piedata.setValue("海尔", 5.5);
piedata.setValue("美的", 17.1);
piedata.setValue("松下", 9.0);
piedata.setValue("科龙", 19.0);
//创建JFreeChart，都使用ChartFactory来创建JFreeChart,很标准的工厂设计模式
JFreeChart chart =
ChartFactory.createPieChart(title, piedata, true, true, true);
//设定图片标题
chart.setTitle(new TextTitle(title, new Font("隶书", Font.ITALIC, 15)));
//chart.addSubtitle(new TextTitle("2002财年分析", new Font("隶书", Font.ITALIC, 12)));
//设定背景
chart.setBackgroundPaint(Color.white);
//chart.s
//饼图使用一个PiePlot 
PiePlot pie = (PiePlot)chart.getPlot();
//pie.setSectionLabelType(PiePlot.NAME_AND_PERCENT_LABELS);
pie.setSectionLabelType(PiePlot.NAME_AND_VALUE_LABELS);
//设定显示格式(名称加百分比或数值)
pie.setPercentFormatString("#,###0.0#%");
//设定百分比显示格式
pie.setBackgroundPaint(Color.white);
pie.setSectionLabelFont(new Font("黑体", Font.TRUETYPE_FONT, 12));
//设定背景透明度（0-1.0之间）
pie.setBackgroundAlpha(0.6f);
//设定前景透明度（0-1.0之间）
pie.setForegroundAlpha(0.90f);
//输出文件到指定目录
String rfname = MathUtil.getRoundCode(12) + ".jpeg";
String fileName = "d:/test/" + rfname;
try {
//可以保存文件为jpg或png格式。
ChartUtilities.saveChartAsJPEG(new File(fileName), 100, chart, 600, 600);
//第一个参数为文件名
//第二个参数质量
//第三个参数为哪个chart创建图片
//第四个宽度
//第五个高度
} catch (IOException exz) {
System.out.print("....Cant't Create image File");
}

// create a default chart based on some sample data...
//曲线图标题
String title = "趋势分析";
//曲线图X轴提示
String domain = "月份走势";
//曲线图Y轴提示
String range = "应收余额";
//曲线图自标题
String subtitleStr = "2003财年分析";
//创建时间数据源
//每一个TimeSeries在图上是一条曲线
TimeSeries ca = new TimeSeries("用友");
for (int i = 1999; i < 2005; i++) {
for (int mon = 0; mon < 12; mon++) {
//ca.add(new Month(mon + 1, i), new Double(500 + Math.random() * 100));
//TimeSeriesDataPair是一个时间点的数值体现
ca.add(
new TimeSeriesDataPair(
new Day(1, mon + 1, i),
new Double(500 + Math.random() * 100)));
}
}
 
TimeSeries ibm = new TimeSeries("金碟");
for (int i = 1999; i < 2005; i++) {
for (int mon = 0; mon < 12; mon++) {
//ibm.add(new Month(mon+1,i),new Double(400-Math.random()*100));
ibm.add(
new TimeSeriesDataPair(
new Day(1, mon + 1, i),
new Double(400 - Math.random() * 100)));
}
}
 
TimeSeries king = new TimeSeries("东软");
for (int i = 1999; i < 2005; i++) {
for (int mon = 0; mon < 12; mon++) {
//ibm.add(new Month(mon+1,i),new Double(400-Math.random()*100));
king.add(
new TimeSeriesDataPair(
new Day(1, mon + 1, i),
new Double(300 - Math.random() * 100)));
}
}
//时间曲线数据集合
TimeSeriesCollection dataset = new TimeSeriesCollection();
dataset.addSeries(ca);
dataset.addSeries(ibm);
dataset.addSeries(king);
//dataset.addSeries(jpy);
//dataset.addSeries(mav);
//时间曲线元素
JFreeChart chart =
ChartFactory.createTimeSeriesChart(
title,
domain,
range,
dataset,
true,
true,
false);
// then customise it a little...
TextTitle subtitle =
new TextTitle(subtitleStr, new Font("黑体", Font.BOLD, 12));
chart.addSubtitle(subtitle);
chart.setTitle(new TextTitle(title, new Font("隶书", Font.ITALIC, 15)));
//pie.setSeriesLabelFont(new Font("黑体", Font.BOLD, 15));
chart.setBackgroundPaint(
new GradientPaint(0, 0, Color.white, 0, 1000, Color.blue));
//sysout
//输出文件到指定目录
String rfname = MathUtil.getRoundCode(22) + ".jpeg";
String fileName = "d:/test/" + rfname;
try {
//for
//System.out.println();
ChartUtilities.saveChartAsJPEG(new File(fileName), 100, chart, 600, 600);
// log.info("....Create image File:" + fileName);
} catch (IOException exz) {
System.out.print("....Cant't Create image File");
}

String title = "柱状图测试";
String domain = "单位比较";
String range = "数值";
//CategoryDataset data = DemoDatasetFactory.createCategoryDataset();
DefaultCategoryDataset data = new DefaultCategoryDataset();
for (int r = 0; r < 5; r++) {
String rowKey = "单位 [" + (r + 1)+"]" ;
//第一层循环：分析对象
for (int c = 0; c < 6; c++) {
//第二层循环：分析对象在时间点上的数据
String columnKey = "2001年" + (c + 1) + "月";
data.addValue(new Double(r * c + 5), rowKey, columnKey);
}
}
 
JFreeChart chart =
ChartFactory.createVerticalBarChart(
title,
domain,
range,
data,
true,
true,
false);
// then customise it a little...
chart.setBackgroundPaint(
new GradientPaint(0, 0, Color.white, 1000, 0, Color.red));
chart.setTitle(new TextTitle(title, new Font("隶书", Font.ITALIC, 15)));
CategoryPlot plot = (CategoryPlot)chart.getPlot();
plot.setForegroundAlpha(0.9f);
plot.setValueLabelFont(new Font("黑体", Font.TRUETYPE_FONT, 12));
//plot.setSectionLabelFont(new Font("黑体", Font.TRUETYPE_FONT, 12));
//注意以下代码
NumberAxis verticalAxis = (NumberAxis)plot.getRangeAxis();
verticalAxis.setStandardTickUnits(NumberAxis.createIntegerTickUnits());
// 输出文件到指定目录
String rfname = MathUtil.getRoundCode(22) + "b.jpeg";
String fileName = "d:/test/" + rfname;
try {
ChartUtilities.saveChartAsJPEG(new File(fileName), 100, chart, 600, 600);
// log.info("....Create image File:" + fileName);
} catch (IOException exz) {
System.out.print("....Cant't Create image File");
}

	int[] bubbleSort(int[] a) {
		//每个都进行冒泡(一个一个来)
		for (int i = 0; i < a.length; i++) {
 
			//和前n-i个比较，把最大的数沉下去
			int temp;
			for (int j = 0; j < a.length - i - 1; j++) {
				if (a[j] > a[j + 1]) {
					//交换
					temp = a[j];
					a[j] = a[j + 1];
					a[j + 1] = temp;
				}
			}
		}
		return a;
	}