AchartEngine柱状图如何一个点显示多个柱状进行对比（有图）

[jxlovqqvo]

求大神帮忙

[dingcaishen]

设四条线 { "一厂":{"1月":"400","2月":"500","3月":"300","4月":"600"}, "二厂"{"1月":"500","2月":"400","3月":"700","4月":"1000"}, "三厂"{"1月":"300","2月":"700","3月":"900","4月":"1200"}, "四厂"{"1月":"900","2月":"1200","3月":"1700","4月":"2000"}, }