Java tutorial
/* * Copyright 2002-2019 the original author or authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * https://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.springframework.jdbc.core.namedparam; import java.beans.PropertyDescriptor; import java.util.ArrayList; import java.util.List; import org.springframework.beans.BeanWrapper; import org.springframework.beans.NotReadablePropertyException; import org.springframework.beans.PropertyAccessor; import org.springframework.beans.PropertyAccessorFactory; import org.springframework.jdbc.core.StatementCreatorUtils; import org.springframework.lang.NonNull; import org.springframework.lang.Nullable; import org.springframework.util.StringUtils; /** * {@link SqlParameterSource} implementation that obtains parameter values * from bean properties of a given JavaBean object. The names of the bean * properties have to match the parameter names. * * <p>Uses a Spring BeanWrapper for bean property access underneath. * * @author Thomas Risberg * @author Juergen Hoeller * @since 2.0 * @see NamedParameterJdbcTemplate * @see org.springframework.beans.BeanWrapper */ public class BeanPropertySqlParameterSource extends AbstractSqlParameterSource { private final BeanWrapper beanWrapper; @Nullable private String[] propertyNames; /** * Create a new BeanPropertySqlParameterSource for the given bean. * @param object the bean instance to wrap */ public BeanPropertySqlParameterSource(Object object) { this.beanWrapper = PropertyAccessorFactory.forBeanPropertyAccess(object); } @Override public boolean hasValue(String paramName) { return this.beanWrapper.isReadableProperty(paramName); } @Override @Nullable public Object getValue(String paramName) throws IllegalArgumentException { try { return this.beanWrapper.getPropertyValue(paramName); } catch (NotReadablePropertyException ex) { throw new IllegalArgumentException(ex.getMessage()); } } /** * Derives a default SQL type from the corresponding property type. * @see org.springframework.jdbc.core.StatementCreatorUtils#javaTypeToSqlParameterType */ @Override public int getSqlType(String paramName) { int sqlType = super.getSqlType(paramName); if (sqlType != TYPE_UNKNOWN) { return sqlType; } Class<?> propType = this.beanWrapper.getPropertyType(paramName); return StatementCreatorUtils.javaTypeToSqlParameterType(propType); } @Override @NonNull public String[] getParameterNames() { return getReadablePropertyNames(); } /** * Provide access to the property names of the wrapped bean. * Uses support provided in the {@link PropertyAccessor} interface. * @return an array containing all the known property names */ public String[] getReadablePropertyNames() { if (this.propertyNames == null) { List<String> names = new ArrayList<>(); PropertyDescriptor[] props = this.beanWrapper.getPropertyDescriptors(); for (PropertyDescriptor pd : props) { if (this.beanWrapper.isReadableProperty(pd.getName())) { names.add(pd.getName()); } } this.propertyNames = StringUtils.toStringArray(names); } return this.propertyNames; } }