Exception in thread "main" net.sf.json.JSONException: java.lang.NoSuchMethodException: Unknown property 'BackCard' on class 'class com.adams.json.User' at net.sf.json.util.PropertySetStrategy$DefaultPropertySetStrategy._setProperty(PropertySetStrategy.java:69) at net.sf.json.util.PropertySetStrategy$DefaultPropertySetStrategy.setProperty(PropertySetStrategy.java:60) at net.sf.json.JSONObject.setProperty(JSONObject.java:1394) at net.sf.json.JSONObject.toBean(JSONObject.java:443) at net.sf.json.JSONObject.toBean(JSONObject.java:233) at com.adams.json.Test.main(Test.java:46) Caused by: java.lang.NoSuchMethodException: Unknown property 'BackCard' on class 'class com.adams.json.User' at org.apache.commons.beanutils.PropertyUtilsBean.setSimpleProperty(PropertyUtilsBean.java:2123) at org.apache.commons.beanutils.PropertyUtils.setSimpleProperty(PropertyUtils.java:890) at net.sf.json.util.PropertySetStrategy$DefaultPropertySetStrategy._setProperty(PropertySetStrategy.java:67) ... 5 more