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new 0c8b1ea0 JEXL: improve example on filter/map;
0c8b1ea0 is described below
commit 0c8b1ea02497e1788288f75390fbad5fd6f95405
Author: Henri Biestro <[email protected]>
AuthorDate: Wed Nov 8 12:06:21 2023 +0100
JEXL: improve example on filter/map;
---
.../apache/commons/jexl3/examples/StreamTest.java | 108 ++++++++++++++++++++-
1 file changed, 103 insertions(+), 5 deletions(-)
diff --git a/src/test/java/org/apache/commons/jexl3/examples/StreamTest.java
b/src/test/java/org/apache/commons/jexl3/examples/StreamTest.java
index 1f72d095..b57cd720 100644
--- a/src/test/java/org/apache/commons/jexl3/examples/StreamTest.java
+++ b/src/test/java/org/apache/commons/jexl3/examples/StreamTest.java
@@ -20,7 +20,10 @@ import static java.lang.Boolean.TRUE;
import java.net.URI;
import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
import java.util.List;
+import java.util.Objects;
import java.util.stream.Collectors;
import java.util.stream.Stream;
@@ -40,7 +43,7 @@ import org.junit.Test;
*/
public class StreamTest {
/**
- * A MapContext that can operate on streams.
+ * A MapContext that can operate on streams and collections.
*/
public static class StreamContext extends MapContext {
/**
@@ -62,6 +65,31 @@ public class StreamTest {
public Stream<?> map(final Stream<?> stream, final JexlScript mapper) {
return stream.map( x -> mapper.execute(this, x));
}
+
+ /**
+ * This allows using a JEXL lambda as a filter.
+ * @param collection the collection
+ * @param filter the lambda to use as filter
+ * @return the filtered result as a list
+ */
+ public List<?> filter(Collection<?> collection, final JexlScript
filter) {
+ return collection.stream()
+ .filter(x -> x != null && TRUE.equals(filter.execute(this, x)))
+ .collect(Collectors.toList());
+ }
+
+ /**
+ * This allows using a JEXL lambda as a mapper.
+ * @param collection the collection
+ * @param mapper the lambda to use as mapper
+ * @return the mapped result as a list
+ */
+ public List<?> map(Collection<?> collection, final JexlScript mapper) {
+ return collection.stream()
+ .map(x -> mapper.execute(this, x))
+ .filter(Objects::nonNull)
+ .collect(Collectors.toList());
+ }
}
/** Our engine instance. */
@@ -76,13 +104,17 @@ public class StreamTest {
// Restricted permissions to a safe set but with URI allowed
final JexlPermissions permissions = new
ClassPermissions(java.net.URI.class);
// Create the engine
- jexl = new
JexlBuilder().features(features).permissions(permissions).create();
+ jexl = new JexlBuilder()
+ .features(features)
+ .permissions(permissions)
+ .namespaces(Collections.singletonMap("URI", java.net.URI.class))
+ .create();
}
@Test
- public void testURIStream() throws Exception {
+ public void testURIStream() {
// let's assume a collection of uris need to be processed and
transformed to be simplified ;
- // we want only http/https ones, only the host part and using an https
scheme
+ // we want only http/https ones, only the host part and using a https
scheme
final List<URI> uris = Arrays.asList(
URI.create("http://[email protected]:8000?qry=true";),
URI.create("https://commons.apache.org/releases/prepare.html";),
@@ -91,7 +123,7 @@ public class StreamTest {
// Create the test control, the expected result of our script
evaluation
final List<?> control = uris.stream()
.map(uri -> uri.getScheme().startsWith("http")? "https://"; +
uri.getHost() : null)
- .filter(x -> x != null)
+ .filter(Objects::nonNull)
.collect(Collectors.toList());
Assert.assertEquals(2, control.size());
@@ -114,4 +146,70 @@ public class StreamTest {
Assert.assertTrue(transformed instanceof List<?>);
Assert.assertEquals(control, transformed);
}
+
+ /**
+ * A MapContext that can operate on streams and collections.
+ */
+ public static class CollectionContext extends MapContext {
+ /**
+ * This allows using a JEXL lambda as a filter.
+ * @param collection the collection
+ * @param filter the lambda to use as filter
+ * @return the filtered result as a list
+ */
+ public List<?> filter(Collection<?> collection, final JexlScript
filter) {
+ return collection.stream()
+ .filter(x -> x != null && TRUE.equals(filter.execute(this, x)))
+ .collect(Collectors.toList());
+ }
+
+ /**
+ * This allows using a JEXL lambda as a mapper.
+ * @param collection the collection
+ * @param mapper the lambda to use as mapper
+ * @return the mapped result as a list
+ */
+ public List<?> map(Collection<?> collection, final JexlScript mapper) {
+ return collection.stream()
+ .map(x -> mapper.execute(this, x))
+ .filter(Objects::nonNull)
+ .collect(Collectors.toList());
+ }
+ }
+
+ @Test
+ public void testURICollection() {
+ // A collection map/filter aware context
+ final JexlContext sctxt = new CollectionContext();
+ // Some uris
+ final List<URI> uris = Arrays.asList(
+ URI.create("http://[email protected]:8000?qry=true";),
+ URI.create("https://commons.apache.org/releases/prepare.html";),
+ URI.create("mailto:[email protected]";)
+ );
+
+ // filter, all results schemes start with 'http'
+ final JexlScript filter = jexl.createScript(
+ "list.filter(uri -> uri.scheme =^ 'http')",
+ "list");
+ final Object filtered = filter.execute(sctxt, uris);
+ Assert.assertTrue(filtered instanceof List<?>);
+ List<URI> result = (List<URI>) filtered;
+ Assert.assertEquals(2, result.size());
+ for(URI uri : result) {
+ Assert.assertTrue(uri.getScheme().startsWith("http"));
+ }
+
+ // map, all results scheme now 'https'
+ final JexlScript mapper = jexl.createScript(
+ "list.map(uri -> uri.scheme =^ 'http'?
URI:create(`https://${uri.host}`) : null)",
+ "list");
+ final Object transformed = mapper.execute(sctxt, uris);
+ Assert.assertTrue(transformed instanceof List<?>);
+ result = (List<URI>) transformed;
+ Assert.assertEquals(2, result.size());
+ for(URI uri : result) {
+ Assert.assertEquals("https", uri.getScheme());
+ }
+ }
}
