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1
52
53 package freemarker.core;
54
55 import java.util.List  ;
56
57 import freemarker.ext.beans.BeansWrapper;
58 import freemarker.template.ObjectWrapper;
59 import freemarker.template.TemplateException;
60 import freemarker.template.TemplateMethodModelEx;
61 import freemarker.template.TemplateModel;
62 import freemarker.template.TemplateModelException;
63 import freemarker.template.TemplateScalarModel;
64 import freemarker.template.utility.ClassUtil;
65
66
71
72 class NewBI extends BuiltIn
73 {
74
75 static final Class TM_CLASS = TemplateModel.class;
76 static final Class BEAN_MODEL_CLASS = freemarker.ext.beans.BeanModel.class;
77 static Class JYTHON_MODEL_CLASS;
78 static {
79 try {
80 JYTHON_MODEL_CLASS = Class.forName("freemarker.ext.jython.JythonModel");
81 } catch (Throwable e) {
82 JYTHON_MODEL_CLASS = null;
83 }
84 }
85
86 TemplateModel _getAsTemplateModel(Environment env)
87 throws TemplateException
88 {
89 TemplateModel tm = target.getAsTemplateModel(env);
90 String classname = null;
91 try {
92 classname = ((TemplateScalarModel) tm).getAsString();
93 }
94 catch (ClassCastException cce) {
95 invalidTypeException(tm, target, env, "string");
96 }
97 catch (NullPointerException npe) {
98 throw new InvalidReferenceException(getStartLocation()
99 + "\nCould not resolve expression: " + target, env);
100 }
101 return new ConstructorFunction(classname, env);
102 }
103
104 class ConstructorFunction implements TemplateMethodModelEx {
105
106 private final Class cl;
107 private final Environment env;
108
109 public ConstructorFunction(String classname, Environment env) throws TemplateException {
110 this.env = env;
111 try {
112 cl = ClassUtil.forName(classname);
113 if (!TM_CLASS.isAssignableFrom(cl)) {
114 throw new TemplateException("Class " + cl.getName() + " does not implement freemarker.template.TemplateModel", env);
115 }
116 if (BEAN_MODEL_CLASS.isAssignableFrom(cl)) {
117 throw new TemplateException("Bean Models cannot be instantiated using the ?new built-in", env);
118 }
119 if (JYTHON_MODEL_CLASS != null && JYTHON_MODEL_CLASS.isAssignableFrom(cl)) {
120 throw new TemplateException("Jython Models cannot be instantiated using the ?new built-in", env);
121 }
122 }
123 catch (ClassNotFoundException cnfe) {
124 throw new TemplateException(cnfe, env);
125 }
126 }
127
128 public Object exec(List arguments) throws TemplateModelException {
129 ObjectWrapper ow = env.getObjectWrapper();
130 BeansWrapper bw =
131 ow instanceof BeansWrapper
132 ? (BeansWrapper)ow
133 : BeansWrapper.getDefaultInstance();
134 return (TemplateModel) bw.newInstance(cl, arguments);
135 }
136 }
137 }
138 |
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