Java tutorial
/** * Copyright (C) 2016 Red Hat, Inc. * * 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 * * http://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 io.syndesis.core.json; import java.io.IOException; import com.fasterxml.jackson.core.JsonParser; import com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackson.core.JsonToken; import com.fasterxml.jackson.databind.DeserializationContext; import com.fasterxml.jackson.databind.JsonDeserializer; /** * Trims JSON strings and converts any empty strings to {@code null}. */ class StringTrimmingJsonDeserializer extends JsonDeserializer<String> { @Override public String deserialize(final JsonParser parser, final DeserializationContext ctxt) throws IOException, JsonProcessingException { final boolean hasStringValue = parser.hasToken(JsonToken.VALUE_STRING); if (!hasStringValue) { return null; } final String text = parser.getText(); final String trimmed = text.trim(); if (trimmed.isEmpty()) { return null; } return trimmed; } }