| 1 | package dolda.jglob; |
| 2 | |
| 3 | import java.util.*; |
| 4 | import java.io.*; |
| 5 | import java.net.*; |
| 6 | import java.lang.annotation.*; |
| 7 | |
| 8 | public class Loader { |
| 9 | private final Class<? extends Annotation> an; |
| 10 | private final ClassLoader cl; |
| 11 | |
| 12 | private Loader(Class<? extends Annotation> annotation, ClassLoader loader) { |
| 13 | this.an = annotation; |
| 14 | this.cl = loader; |
| 15 | } |
| 16 | |
| 17 | public Iterable<String> names() { |
| 18 | return(new Iterable<String>() { |
| 19 | public Iterator<String> iterator() { |
| 20 | return(new Iterator<String>() { |
| 21 | private Enumeration<URL> rls; |
| 22 | private Iterator<String> cur = null; |
| 23 | |
| 24 | private Iterator<String> parse(URL url) { |
| 25 | try { |
| 26 | List<String> buf = new LinkedList<String>(); |
| 27 | InputStream in = url.openStream(); |
| 28 | try { |
| 29 | BufferedReader r = new BufferedReader(new InputStreamReader(in, "utf-8")); |
| 30 | String ln; |
| 31 | while((ln = r.readLine()) != null) { |
| 32 | ln = ln.trim(); |
| 33 | if(ln.length() < 1) |
| 34 | continue; |
| 35 | buf.add(ln); |
| 36 | } |
| 37 | return(buf.iterator()); |
| 38 | } finally { |
| 39 | in.close(); |
| 40 | } |
| 41 | } catch(IOException e) { |
| 42 | throw(new GlobAccessException(e)); |
| 43 | } |
| 44 | } |
| 45 | |
| 46 | public boolean hasNext() { |
| 47 | if((cur == null) || !cur.hasNext()) { |
| 48 | if(rls == null) { |
| 49 | try { |
| 50 | rls = cl.getResources("META-INF/glob/" + an.getName()); |
| 51 | } catch(IOException e) { |
| 52 | throw(new GlobAccessException(e)); |
| 53 | } |
| 54 | } |
| 55 | if(!rls.hasMoreElements()) |
| 56 | return(false); |
| 57 | URL u = rls.nextElement(); |
| 58 | cur = parse(u); |
| 59 | } |
| 60 | return(true); |
| 61 | } |
| 62 | |
| 63 | public String next() { |
| 64 | if(!hasNext()) |
| 65 | throw(new NoSuchElementException()); |
| 66 | String ret = cur.next(); |
| 67 | return(ret); |
| 68 | } |
| 69 | |
| 70 | public void remove() {throw(new UnsupportedOperationException());} |
| 71 | }); |
| 72 | } |
| 73 | }); |
| 74 | } |
| 75 | |
| 76 | public Iterable<Class<?>> classes() { |
| 77 | return(new Iterable<Class<?>>() { |
| 78 | public Iterator<Class<?>> iterator() { |
| 79 | return(new Iterator<Class<?>>() { |
| 80 | private final Iterator<String> names = names().iterator(); |
| 81 | private Class<?> n = null; |
| 82 | |
| 83 | public boolean hasNext() { |
| 84 | while(n == null) { |
| 85 | if(!names.hasNext()) |
| 86 | return(false); |
| 87 | String nm = names.next(); |
| 88 | Class<?> c; |
| 89 | try { |
| 90 | c = cl.loadClass(nm); |
| 91 | } catch(ClassNotFoundException e) { |
| 92 | continue; |
| 93 | } |
| 94 | if(c.getAnnotation(an) == null) |
| 95 | continue; |
| 96 | n = c; |
| 97 | } |
| 98 | return(true); |
| 99 | } |
| 100 | |
| 101 | public Class<?> next() { |
| 102 | if(!hasNext()) |
| 103 | throw(new NoSuchElementException()); |
| 104 | Class<?> r = n; |
| 105 | n = null; |
| 106 | return(r); |
| 107 | } |
| 108 | |
| 109 | public void remove() {throw(new UnsupportedOperationException());} |
| 110 | }); |
| 111 | } |
| 112 | }); |
| 113 | } |
| 114 | |
| 115 | public <T> Iterable<T> instances(final Class<T> cast) { |
| 116 | return(new Iterable<T>() { |
| 117 | public Iterator<T> iterator() { |
| 118 | return(new Iterator<T>() { |
| 119 | private final Iterator<Class<?>> classes = classes().iterator(); |
| 120 | private T n = null; |
| 121 | |
| 122 | public boolean hasNext() { |
| 123 | while(n == null) { |
| 124 | if(!classes.hasNext()) |
| 125 | return(false); |
| 126 | Class<?> cl = classes.next(); |
| 127 | T inst; |
| 128 | try { |
| 129 | inst = cast.cast(cl.newInstance()); |
| 130 | } catch(InstantiationException e) { |
| 131 | throw(new GlobInstantiationException(e)); |
| 132 | } catch(IllegalAccessException e) { |
| 133 | throw(new GlobInstantiationException(e)); |
| 134 | } |
| 135 | n = inst; |
| 136 | } |
| 137 | return(true); |
| 138 | } |
| 139 | |
| 140 | public T next() { |
| 141 | if(!hasNext()) |
| 142 | throw(new NoSuchElementException()); |
| 143 | T r = n; |
| 144 | n = null; |
| 145 | return(r); |
| 146 | } |
| 147 | |
| 148 | public void remove() {throw(new UnsupportedOperationException());} |
| 149 | }); |
| 150 | } |
| 151 | }); |
| 152 | } |
| 153 | |
| 154 | public Iterable<?> instances() { |
| 155 | return(instances(Object.class)); |
| 156 | } |
| 157 | |
| 158 | public static Loader get(Class<? extends Annotation> annotation, ClassLoader loader) { |
| 159 | return(new Loader(annotation, loader)); |
| 160 | } |
| 161 | |
| 162 | public static Loader get(Class<? extends Annotation> annotation) { |
| 163 | return(get(annotation, annotation.getClassLoader())); |
| 164 | } |
| 165 | } |