Java 替换字符“时出现空指针异常”;没有文本,然后将值强制转换为浮动
我正在编写一个java程序,通过HTTP GET方法获取JSON数据,在导航对象树后,它返回以下内容:Java 替换字符“时出现空指针异常”;没有文本,然后将值强制转换为浮动,java,json,http,get,getjson,Java,Json,Http,Get,Getjson,我正在编写一个java程序,通过HTTP GET方法获取JSON数据,在导航对象树后,它返回以下内容: { "year":"2015", "period":"M03", "periodName":"March", "value":"141178", "footnotes":[{}] } 现在我想把它的价值和等级划分成一个浮动,我试着这样做: JSONParser parser = new JSONParser(); try { JSONObject BLSemployment
{
"year":"2015",
"period":"M03",
"periodName":"March",
"value":"141178",
"footnotes":[{}]
}
现在我想把它的价值和等级划分成一个浮动,我试着这样做:
JSONParser parser = new JSONParser();
try
{
JSONObject
BLSemployment = ( JSONObject ) parser.parse( _RDATA );
BLSemployment = ( ( JSONObject ) BLSemployment.get( "Results" ) );
JSONArray
BLSemploymentseries = ( ( JSONArray ) BLSemployment.get( "series" ) );
BLSemployment = ( ( JSONObject ) BLSemploymentseries.get( 0 ) );
BLSemploymentseries = ( ( JSONArray ) BLSemployment.get( "data" ) );
for( int i = 0; i < 12; i++ )
{
BLSemployment = ( (JSONObject) BLSemploymentseries.get( i ) );
HistoricalNonFarmPayrollData[i] = Float.parseFloat( JSONValue.toJSONString( BLSemployment.get( "value" ) ).replace( "\"" , "" ) );
HistoricalNonFarmPayrollYear[i] = JSONValue.toJSONString( BLSemployment.get( "year" ) );
HistoricalNonFarmPayrollMonth[i] = JSONValue.toJSONString( BLSemployment.get( "periodName" ) );
}
}
catch ( ParseException pe )
{
System.out.println( pe );
}
已解决:偶尔BLS网站在一段时间内不发送数据,而我在这段时间内编码。已解决:偶尔BLS网站在一段时间内不发送数据,而我在这段时间内编码。将行拆分为几行,查看
null
是什么,或者使用调试器!我不理解这一部分HistoricalNonFarmPayrollData[I]=Float.parseFloat(JSONValue.toJSONString(BLSemployment.get(“value”)).replace(“\”,”);BLSemployment.get(“value”)似乎已经返回字符串。不应该是?HistoricalNonFarmPayrollData[I]=Float.parseFloat(BLSemployment.get(“value”));您没有放入引发异常的代码。您也应该发布该异常。将该行拆分为几行,然后查看null
是什么,或者使用调试器!我不理解这部分历史性的nonfarmpayrolldata[I]=Float.parseFloat(JSONValue.toJSONString(BLSemployment.get(“value”)。替换(“\”,” ) ); BLSemployment.get(“value”)似乎已返回字符串。不应该吗?HistoricalNonFarmPayrollData[i]=Float.parseFloat(BLSemployment.get(“value”);您没有放入引发异常的代码。你也应该把它贴出来。可能是
Exception in thread "main" java.lang.NullPointerException
at BLSFramework.getNonFarmPayrolls(playground.java:354)
at playground.main(playground.java:27)