Adds setting ACL permissions by mode string

Signed-off-by: Patrick Reinhart <patrick@reini.net>

Author: reinhapa

src/main/java/org/xmldb/api/security/AclEntry.java

@@ -185,6 +185,41 @@ public Builder setPermissions(AclEntryPermission... perms) {
       return this;
     }
 
+    /**
+     * Sets the permissions component of this builder. On return, the permissions component of this
+     * builder is a copy of the permissions in the given array.
+     *
+     * @param modeStr the permissions mode string
+     * @return this builder
+     */
+    public Builder setPermissions(String modeStr) {
+      Set<AclEntryPermission> set = EnumSet.noneOf(AclEntryPermission.class);
+      if (modeStr == null || modeStr.isEmpty() || modeStr.length() > 3) {
+        throw new IllegalArgumentException("Invalid mode string '" + modeStr + "'");
+      }
+      for (int index = 0; index < 3; index++) {
+        char chr = modeStr.charAt(index);
+        switch (chr) {
+          case 'r':
+            set.add(AclEntryPermission.READ);
+            break;
+          case 'w':
+            set.add(AclEntryPermission.WRITE);
+            break;
+          case 'x':
+            set.add(AclEntryPermission.EXECUTE);
+            break;
+          case '-':
+            break;
+          default:
+            throw new IllegalArgumentException(
+                "Unknown char '" + chr + "' in mode string '" + modeStr + "'");
+        }
+      }
+      this.permissions = set;
+      return this;
+    }
+
     /**
      * Sets the flags component of this builder. On return, the flags component of this builder is a
      * copy of the given set.

src/test/java/org/xmldb/api/security/AclEntryTest.java

@@ -125,6 +125,32 @@ void testBuildWithPermissionsVarargs() {
     });
   }
 
+  @Test
+  void testBuildWithPermissionsModeString() {
+    assertThatExceptionOfType(IllegalArgumentException.class)
+        .isThrownBy(() -> builder.setPermissions((String) null))
+        .withMessage("Invalid mode string 'null'");
+    assertThatExceptionOfType(IllegalArgumentException.class)
+        .isThrownBy(() -> builder.setPermissions("")).withMessage("Invalid mode string ''");
+    assertThatExceptionOfType(IllegalArgumentException.class)
+        .isThrownBy(() -> builder.setPermissions("xxxx")).withMessage("Invalid mode string 'xxxx'");
+    assertThatExceptionOfType(IllegalArgumentException.class)
+        .isThrownBy(() -> builder.setPermissions("a"))
+        .withMessage("Unknown char 'a' in mode string 'a'");
+    builder.setType(ALLOW).setPrincipal(principal).setPermissions("rw-");
+    assertThat(builder.build()).satisfies(aclEntry -> {
+      assertThat(aclEntry.type()).isEqualTo(ALLOW);
+      assertThat(aclEntry.permissions()).containsExactlyInAnyOrder(READ, WRITE)
+          .isInstanceOf(EnumSet.class);
+    });
+    builder.setType(ALLOW).setPrincipal(principal).setPermissions("r-x");
+    assertThat(builder.build()).satisfies(aclEntry -> {
+      assertThat(aclEntry.type()).isEqualTo(ALLOW);
+      assertThat(aclEntry.permissions()).containsExactlyInAnyOrder(READ, EXECUTE)
+          .isInstanceOf(EnumSet.class);
+    });
+  }
+
   @Test
   void testBuildWithEmpptyFlagsSet() {
     builder.setType(DENY).setPrincipal(principal);