From 1dccedcd1da675870c771aceac722b9d29e863a5 Mon Sep 17 00:00:00 2001 From: Dmytry Kovalenko Date: Mon, 2 May 2022 19:11:24 +0300 Subject: [PATCH] [BAEL-5553] Check whether a string is valid JSON in Java (#12136) * [BAEL-5553] Check whether a string is valid JSON in Java * [BAEL-5553] Move implementation to json-2 package * [BAEL-5553] Move mapper creation outside method --- json-2/pom.xml | 6 ++++ .../jsonvalidation/GsonValidator.java | 32 +++++++++++++++++ .../jsonvalidation/JacksonValidator.java | 18 ++++++++++ .../jsonvalidation/JsonValidator.java | 30 ++++++++++++++++ .../jsonvalidation/GsonValidatorUnitTest.java | 35 +++++++++++++++++++ .../JacksonValidatorUnitTest.java | 29 +++++++++++++++ .../jsonvalidation/JsonValidatorUnitTest.java | 35 +++++++++++++++++++ 7 files changed, 185 insertions(+) create mode 100644 json-2/src/main/java/com/baeldung/jsonvalidation/GsonValidator.java create mode 100644 json-2/src/main/java/com/baeldung/jsonvalidation/JacksonValidator.java create mode 100644 json-2/src/main/java/com/baeldung/jsonvalidation/JsonValidator.java create mode 100644 json-2/src/test/java/com/baeldung/jsonvalidation/GsonValidatorUnitTest.java create mode 100644 json-2/src/test/java/com/baeldung/jsonvalidation/JacksonValidatorUnitTest.java create mode 100644 json-2/src/test/java/com/baeldung/jsonvalidation/JsonValidatorUnitTest.java diff --git a/json-2/pom.xml b/json-2/pom.xml index 751199d394..3e12fccc29 100644 --- a/json-2/pom.xml +++ b/json-2/pom.xml @@ -14,6 +14,11 @@ + + org.json + json + ${json.version} + com.alibaba fastjson @@ -148,6 +153,7 @@ 0.9.23 1.9.2 1.2.21 + 20211205 \ No newline at end of file diff --git a/json-2/src/main/java/com/baeldung/jsonvalidation/GsonValidator.java b/json-2/src/main/java/com/baeldung/jsonvalidation/GsonValidator.java new file mode 100644 index 0000000000..841513fc28 --- /dev/null +++ b/json-2/src/main/java/com/baeldung/jsonvalidation/GsonValidator.java @@ -0,0 +1,32 @@ +package com.baeldung.jsonvalidation; + +import java.io.IOException; + +import com.google.gson.Gson; +import com.google.gson.JsonElement; +import com.google.gson.JsonParser; +import com.google.gson.JsonSyntaxException; +import com.google.gson.TypeAdapter; + +public class GsonValidator { + + final TypeAdapter strictAdapter = new Gson().getAdapter(JsonElement.class); + + public boolean isValid(String json) { + try { + JsonParser.parseString(json); + } catch (JsonSyntaxException e) { + return false; + } + return true; + } + + public boolean isValidStrict(String json) { + try { + strictAdapter.fromJson(json); + } catch (JsonSyntaxException | IOException e) { + return false; + } + return true; + } +} diff --git a/json-2/src/main/java/com/baeldung/jsonvalidation/JacksonValidator.java b/json-2/src/main/java/com/baeldung/jsonvalidation/JacksonValidator.java new file mode 100644 index 0000000000..8c339f46c8 --- /dev/null +++ b/json-2/src/main/java/com/baeldung/jsonvalidation/JacksonValidator.java @@ -0,0 +1,18 @@ +package com.baeldung.jsonvalidation; + +import com.fasterxml.jackson.core.JacksonException; +import com.fasterxml.jackson.databind.ObjectMapper; + +public class JacksonValidator { + + final ObjectMapper mapper = new ObjectMapper(); + + public boolean isValid(String json) { + try { + mapper.readTree(json); + } catch (JacksonException e) { + return false; + } + return true; + } +} diff --git a/json-2/src/main/java/com/baeldung/jsonvalidation/JsonValidator.java b/json-2/src/main/java/com/baeldung/jsonvalidation/JsonValidator.java new file mode 100644 index 0000000000..e4183e2322 --- /dev/null +++ b/json-2/src/main/java/com/baeldung/jsonvalidation/JsonValidator.java @@ -0,0 +1,30 @@ +package com.baeldung.jsonvalidation; + +import org.json.JSONArray; +import org.json.JSONException; +import org.json.JSONObject; + +public class JsonValidator { + + public boolean isValidObject(String json) { + try { + new JSONObject(json); + } catch (JSONException e) { + return false; + } + return true; + } + + public boolean isValidJson(String json) { + try { + new JSONObject(json); + } catch (JSONException e) { + try { + new JSONArray(json); + } catch (JSONException ne) { + return false; + } + } + return true; + } +} diff --git a/json-2/src/test/java/com/baeldung/jsonvalidation/GsonValidatorUnitTest.java b/json-2/src/test/java/com/baeldung/jsonvalidation/GsonValidatorUnitTest.java new file mode 100644 index 0000000000..3b8989bdb5 --- /dev/null +++ b/json-2/src/test/java/com/baeldung/jsonvalidation/GsonValidatorUnitTest.java @@ -0,0 +1,35 @@ +package com.baeldung.jsonvalidation; + +import static org.junit.Assert.assertFalse; +import static org.junit.Assert.assertTrue; + +import org.junit.Test; + +public class GsonValidatorUnitTest { + + private final GsonValidator validator = new GsonValidator(); + + @Test + public void givenValidObjectJson_whenValidatingNonStrict_thenValid() { + String json = "{\"email\": \"example@com\", \"name\": \"John\"}"; + assertTrue(validator.isValid(json)); + } + + @Test + public void givenValidArrayJson_whenValidatingNonStrict_thenValid() { + String json = "[{\"email\": \"example@com\", \"name\": \"John\"},{\"email\": \"example1@com\", \"name\": \"Bob\"}]"; + assertTrue(validator.isValid(json)); + } + + @Test + public void givenInvalidJson_whenValidatingNonStrict_thenValid() { + String json = "Invalid_Json"; + assertTrue(validator.isValid(json)); + } + + @Test + public void givenInvalidJson_whenValidatingStrict_thenInvalid() { + String json = "Invalid_Json"; + assertFalse(validator.isValidStrict(json)); + } +} diff --git a/json-2/src/test/java/com/baeldung/jsonvalidation/JacksonValidatorUnitTest.java b/json-2/src/test/java/com/baeldung/jsonvalidation/JacksonValidatorUnitTest.java new file mode 100644 index 0000000000..b633af7fdc --- /dev/null +++ b/json-2/src/test/java/com/baeldung/jsonvalidation/JacksonValidatorUnitTest.java @@ -0,0 +1,29 @@ +package com.baeldung.jsonvalidation; + +import static org.junit.Assert.assertFalse; +import static org.junit.Assert.assertTrue; + +import org.junit.Test; + +public class JacksonValidatorUnitTest { + + private final JacksonValidator validator = new JacksonValidator(); + + @Test + public void givenValidObjectJson_whenValidating_thenValid() { + String json = "{\"email\": \"example@com\", \"name\": \"John\"}"; + assertTrue(validator.isValid(json)); + } + + @Test + public void givenValidArrayJson_whenValidating_thenValid() { + String json = "[{\"email\": \"example@com\", \"name\": \"John\"},{\"email\": \"example1@com\", \"name\": \"Bob\"}]"; + assertTrue(validator.isValid(json)); + } + + @Test + public void givenInvalidJson_whenValidating_thenInvalid() { + String json = "Invalid_Json"; + assertFalse(validator.isValid(json)); + } +} diff --git a/json-2/src/test/java/com/baeldung/jsonvalidation/JsonValidatorUnitTest.java b/json-2/src/test/java/com/baeldung/jsonvalidation/JsonValidatorUnitTest.java new file mode 100644 index 0000000000..a590b3f709 --- /dev/null +++ b/json-2/src/test/java/com/baeldung/jsonvalidation/JsonValidatorUnitTest.java @@ -0,0 +1,35 @@ +package com.baeldung.jsonvalidation; + +import static org.junit.Assert.assertFalse; +import static org.junit.Assert.assertTrue; + +import org.junit.Test; + +public class JsonValidatorUnitTest { + + private final JsonValidator validator = new JsonValidator(); + + @Test + public void givenValidObjectJson_whenValidatingObject_thenValid() { + String json = "{\"email\": \"example@com\", \"name\": \"John\"}"; + assertTrue(validator.isValidObject(json)); + } + + @Test + public void givenInvalidJson_whenValidating_thenInvalid() { + String json = "Invalid_Json"; + assertFalse(validator.isValidObject(json)); + } + + @Test + public void givenValidArrayJson_whenValidatingObject_thenInvalid() { + String json = "[{\"email\": \"example@com\", \"name\": \"John\"},{\"email\": \"example1@com\", \"name\": \"Bob\"}]"; + assertFalse(validator.isValidObject(json)); + } + + @Test + public void givenValidJson_whenValidatingJson_thenValid() { + String json = "[{\"email\": \"example@com\", \"name\": \"John\"},{\"email\": \"example1@com\", \"name\": \"Bob\"}]"; + assertTrue(validator.isValidJson(json)); + } +}