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http断点续传简单实现(java)

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/* zZPWE "u}  
**SiteFileFetch.java 7xO05)bz  
*/ D$4GNeB+#  
package NetFox; 'z,kxra|n  
import java.io.*; \5&Mg81  
import java.net.*; R98YGW_ dT  
^@8XJ[C,_  
`},:dDHI  
public class SiteFileFetch extends Thread { :k ?`gm$  
;/kd.Q  
B|a<=~  
SiteInfoBean siteInfoBean = null; //文件信息Bean Dk sn  
long[] nStartPos; //开始位置 Drtg7v{@\  
long[] nEndPos; //结束位置 OKm,iIp]  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ?bM%#x{e  
long nFileLength; //文件长度 +o4o!;E)  
boolean bFirst = true; //是否第一次取文件 Wjq9f;  
boolean bStop = false; //停止标志 ]Xa]a}[uE  
File tmpFile; //文件下载的临时信息 LE{@J0r#n  
DataOutputStream output; //输出到文件的输出流 Sak^J.~G[  
;6R9k]5P%  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) kJ"rRsK  
public SiteFileFetch(SiteInfoBean bean) throws IOException kwUUvF7w  
{ 9Br+]F _i  
siteInfoBean = bean; g7?[}?]3"p  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 8K 9HFT@yV  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); w^8Q~ 3|7  
if(tmpFile.exists ()) |sr\SCx  
{ 9^g8VlQdT  
bFirst = false; sx azl]  
read_nPos(); !VIxEu^ke  
} }iDRlE,  
else C ibfuR  
{ Dti-*LB1  
nStartPos = new long[bean.getNSplitter()]; PTe$dPB  
nEndPos = new long[bean.getNSplitter()]; 5P<1I7d  
} 0vLx={i  
1J1Jp|j.  
gYN;F u-9Z  
A4(L47^  
} KB~1]cYMp  
"Cxj_V@\  
16eP7s  
public void run() [dLc+h1{B  
{ `:Wyw<^  
//获得文件长度 !NNPg?Y  
//分割文件 z =H?@z  
//实例FileSplitterFetch `f}ZAX  
//启动FileSplitterFetch线程 !-T#dU  
//等待子线程返回 037\LPO  
try{ s1]Pv/a=y  
if(bFirst) z)KoK`\mE"  
{ h(nE)j  
nFileLength = getFileSize(); s[{8:Px  
if(nFileLength == -1) Ay6T*Nu`  
{ 9nQyPb6  
System.err.println("File Length is not known!"); ApSseBhh  
} P\WHM(  
else if(nFileLength == -2) }P%gwgPK  
{ $I-iq @  
System.err.println("File is not access!"); 3F;0a ;[  
} m`zd0IRTP  
else w7~]c,$y.  
{ 1f^oW[w&  
for(int i=0;i<nStartPos.length;i++) } %0 w25  
{ z|AknEE,  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); &/uakkS  
} U[;ECw@  
for(int i=0;i<nEndPos.length-1;i++) exSwx-zxI  
{ TuCHD~rb  
nEndPos = nStartPos[i+1]; 1 c"s+k]9  
} @Z$fEG)9  
nEndPos[nEndPos.length-1] = nFileLength; p=[dt  
} 7Y~5gn  
} u* iqwm.  
b*| ?7  
|1ry*~  
//启动子线程 (*eX'^Q)d  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; rA<J^dX=C  
for(int i=0;i<nStartPos.length;i++) :FSg%IUX  
{ :W&kl UU"  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), GPAC0K^p  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), vr47PM2al  
nStartPos,nEndPos,i); (.oDxs()I  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FLPN#1  
fileSplitterFetch.start(); Th,]nVsGs~  
} E.$//P n|1  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @:hWahMy  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); W{ozZuo  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", AS0(NlV  
nEndPos = " + nFileLength); _kOuD}_|  
// fileSplitterFetch[nPos.length-1].start(); i-0AcN./p  
T06w`'aL  
<5]_u:  
//等待子线程结束 4mBM5Tv  
//int count = 0; UlN}SddI9  
//是否结束while循环 /Y\q&}  
boolean breakWhile = false; -{eiV0<^  
7je1vNs  
T;3~teVYB  
while(!bStop) c?xeBC1-  
{ vA*NJ%&`  
write_nPos(); ZQz;EV!  
Utility.sleep(500); {XhpxJ__  
breakWhile = true; )}w-;HX  
2s 9U&  
'uUa|J1mu  
for(int i=0;i<nStartPos.length;i++) Jz;`L3m  
{ z SsogAx  
if(!fileSplitterFetch.bDownOver) *qMjoP,  
{ k3OnvnJb  
breakWhile = false; &n6 |L8  
break; Z+J~moW `  
} N9)ERW2`*  
} /$vX1T  
if(breakWhile) QBoX3w=  
break; @J@bD+Q+0  
K1<l/ s  
N/^[c+J  
//count++; l%2B4d9"v  
//if(count>4) 1 d.>?^uE  
// siteStop(); wL0"1Ya  
} kgmb<4p  
jS/$ o?  
U/(R_U>=  
System.err.println("文件下载结束!"); jaux:fU  
} dnPr2oI?I  
catch(Exception e){e.printStackTrace ();} ~}~ yR*K%  
} \BsvUGd  
WWTJ%Rd|  
yNx"Ey dk`  
//获得文件长度 XnvaT(k7Y  
public long getFileSize() 8{Svax(  
{ I#p-P)Q%S  
int nFileLength = -1; )./'RE+(k  
try{ A,ao2)  
URL url = new URL(siteInfoBean.getSSiteURL()); Q([g1?F9*  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v#IZSBvuQK  
httpConnection.setRequestProperty("User-Agent","NetFox"); 8>:2li  
HoM8V"8B  
VxAR,a1+n  
int responseCode=httpConnection.getResponseCode(); J Y> I  
if(responseCode>=400) wIbc8ze  
{ uoBPi[nK  
processErrorCode(responseCode); ,%m$_wA$  
return -2; //-2 represent access is error gD fVY%[Z  
} pm;g)p?  
7@VR:~n}k  
JeCEj=_Z  
String sHeader; X_|} b[b  
}fxH>79g  
-3b0;L&4>x  
for(int i=1;;i++) [ 06B)|s  
{ r?2C%GI`  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); X4*/h$48 w  
//Utility.log(in.readLine()); *KV] MdS  
sHeader=httpConnection.getHeaderFieldKey(i); qm}7w3I^  
if(sHeader!=null) 55|$Imnf  
{ g(;ejKSR  
if(sHeader.equals("Content-Length")) N=L urXv  
{ 7~`6~qg.  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); DFjkp;`1  
break; tv|=`~Y  
} )ZmE"  
} Bp6Evi  
else -XY]WWlq  
break; ||,;07  
} ]X _&  
} j({L6</x  
catch(IOException e){e.printStackTrace ();} Ap>n4~  
catch(Exception e){e.printStackTrace ();} !! K=v7M  
,|c_l)  
\S2'3SD d/  
Utility.log(nFileLength); Wj*6}N/  
wy&*6>.  
O "h+i>|l  
return nFileLength; n:!J3pR  
} I2l'y8)d  
,wEM  
{k]VT4/  
//保存下载信息(文件指针位置) `RzM)ILl  
private void write_nPos() =XS'V*  
{ P?uKDON  
try{ V+K.' J ^@  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,[hJi3xM  
output.writeInt(nStartPos.length); {DO9{96w4  
for(int i=0;i<nStartPos.length;i++) 0UB'6wRVo  
{ XKK*RVs#  
// output.writeLong(nPos); BR%:`uiQ<  
output.writeLong(fileSplitterFetch.nStartPos); E|Lh$9XONA  
output.writeLong(fileSplitterFetch.nEndPos); n*xNMw1x"T  
} 1-[{4{R  
output.close(); (jyJ-qe  
} xX>448=  
catch(IOException e){e.printStackTrace ();} U)o8Tr  
catch(Exception e){e.printStackTrace ();} LOYv%9$0*p  
} jH G(d$h  
aH#|LrdJ  
~gDtj&F  
//读取保存的下载信息(文件指针位置) FxT [4  
private void read_nPos() V)Xcn'h  
{ zj)[Sn tn?  
try{ DpR%s",Q  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8ksDXf`.  
int nCount = input.readInt(); V!=]a^]:  
nStartPos = new long[nCount]; \d;Ow8%d/  
nEndPos = new long[nCount]; LMDa68 s  
for(int i=0;i<nStartPos.length;i++) 8+W^t I  
{ )G|U B8]  
nStartPos = input.readLong(); Mt:(w;Y  
nEndPos = input.readLong(); `'QPe42  
} t8[:}[Jx  
input.close(); ZtT`_G&  
} pL-$Np] V  
catch(IOException e){e.printStackTrace ();} j)5Vv K\  
catch(Exception e){e.printStackTrace ();} i xyjl[G  
} 1FX-#Y`e  
Ek BM>*W  
mnia>; 0H  
private void processErrorCode(int nErrorCode) }?^G= IP4(  
{ Z~gqTB]H  
System.err.println("Error Code : " + nErrorCode); Mf63 59  
} iB`m!g6$  
oAx0$]+%V)  
YD%Kd&es  
//停止文件下载 +Lr0i_al  
public void siteStop() N!3f1d7RQ  
{ ;vx9xs?6  
bStop = true; HTG;'$H^  
for(int i=0;i<nStartPos.length;i++) /P%:u0fX,  
fileSplitterFetch.splitterStop(); dd+).*  
b6(yyYdF  
Bk F[nL*|  
} G~Sfpf  
} re*/JkDq3K  
//负责部分文件的抓取 ;D7jE+  
**FileSplitterFetch.java A!~o?ej  
*/ ^pP 14y*go  
package NetFox; gs3}rW  
A.FI] K@  
k|D!0^HE[  
import java.io.*; VGq]id{*$  
import java.net.*; %Z? o]  
2P}RZvUd  
#wyS?FP-  
public class FileSplitterFetch extends Thread { UTt#ltun?  
Id0F2  [  
;a`X|N9  
String sURL; //File URL ~83P09\T%  
long nStartPos; //File Snippet Start Position 1DP)6{x  
long nEndPos; //File Snippet End Position yN.D(ZwF:  
int nThreadID; //Thread's ID G dU W$.  
boolean bDownOver = false; //Downing is over %ab79RS]C  
boolean bStop = false; //Stop identical jo*9QO  
FileAccessI fileAccessI = null; //File Access interface -G 'lyH  
e{,/  
mI%/k7:sf  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException NsHveOK1.  
{ QFYy$T+W  
this.sURL = sURL; a6d KQ3D  
this.nStartPos = nStart; Xn=fLb(  
this.nEndPos = nEnd; K;l'IN"N  
nThreadID = id; c"ztrKQQ  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 'Ap 5Aq  
} nmGHJb,$  
a5M>1&j/eC  
V]}b3Y!(  
public void run() Vvj]2V3  
{ jlBCu(.,_  
while(nStartPos < nEndPos && !bStop) }t'^Au`X  
{ fL;p^t u3  
h~p}08  
jHCKV  
try{ rzHa&:Y  
URL url = new URL(sURL); Fe .*O`  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O@rb4(  
httpConnection.setRequestProperty("User-Agent","NetFox"); pg)g&ifKl  
String sProperty = "bytes="+nStartPos+"-"; !*gAGt_  
httpConnection.setRequestProperty("RANGE",sProperty); >``GDjcJ  
Utility.log(sProperty); ,GIqRT4K  
|Y11sDa9h  
]r6bJ 2  
InputStream input = httpConnection.getInputStream(); Bl];^W^P  
//logResponseHead(httpConnection); mtHz6+  
$@)d9u cd  
HV.7IyBA^  
byte[] b = new byte[1024]; #8jd,I% L  
int nRead; 3)a29uc:U  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ltR^IiA}  
{ (SK5pU  
nStartPos += fileAccessI.write(b,0,nRead); ]w>fnew  
//if(nThreadID == 1) FF/R_xnx  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E,@UM$alP  
} df& |Lc1J  
[B`P]}gL:  
;G]'}$`/q  
Utility.log("Thread " + nThreadID + " is over!"); -; $/<  
bDownOver = true; =1 \wZuK#  
//nPos = fileAccessI.write (b,0,nRead); .<%M8rcj  
} ud D[hPJd  
catch(Exception e){e.printStackTrace ();} 59J9V3na  
} UAZ&*{MM^  
} hJsC \C,^  
4 G[hU4L  
Yur)_m  
//打印回应的头信息 YPnJldVn  
public void logResponseHead(HttpURLConnection con) u0b-JJ7)BQ  
{ sEyl\GL  
for(int i=1;;i++) S45>f(!  
{ 5i#w:O\cz  
String header=con.getHeaderFieldKey(i); ^^l"brPa  
if(header!=null) h+D=/:B  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); YWrY{6M  
Utility.log(header+" : "+con.getHeaderField(header)); .`N` M9  
else 'Y\"^'OU\  
break; @98SC}}u  
} %)Dd{|c  
} UE w3AO  
T9-a uK0d  
yW?%c#9D  
public void splitterStop() \r,. hUp  
{ Tpx,41(k  
bStop = true; 98'XSL|  
} %0]b5u  
[_b='/8  
}Xv1KX'  
} 1iL xXd  
}F6b ]  
G | oG:  
/* }tO<_f))  
**FileAccess.java }yDq\5s Q[  
*//文件访问(定位,写) {NgY8w QB  
package NetFox; gEHfsR=D6  
import java.io.*; ArzsZ<\//  
d ovwB`5  
S@NhEc  
public class FileAccessI implements Serializable{ 3MJWCo-[  
9= $,]M  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =3dbw8I  
RandomAccessFile oSavedFile; <|Eby!KXR  
long nPos; |S`yXsg  
'xoE [0!  
@k6}4O?{  
public FileAccessI() throws IOException ?9@Af{b t2  
{ I} fcFL8  
this("",0); {<[tYZmj.  
} b:cK>fh0_  
~{Rt4o _W  
KVpAV$|e  
public FileAccessI(String sName,long nPos) throws IOException SLOYlRGCi  
{ 9~%]|_(  
oSavedFile = new RandomAccessFile(sName,"rw"); PFgjWp"Y  
this.nPos = nPos; l'". }6S  
oSavedFile.seek(nPos); 42wC."A  
}  >E ;o"  
edk9Qd9  
_XNR um4  
public synchronized int write(byte[] b,int nStart,int nLen) <sYw%9V  
{ 7C7(bg,7^  
int n = -1;  / !  
try{ 0*/ r'  
oSavedFile.write(b,nStart,nLen); !_H8Q}a  
n = nLen; |SukiXJZF  
} f<4q]HCa  
catch(IOException e) )X!DCL:16  
{ O8~U<'=*  
e.printStackTrace (); JX$NEq(  
} (g2r\hI  
NF(IF.8G  
XAxI?y[c  
return n; `m;"I  
} Q[Sd  
@TPgA(5NR  
$0 S#d@v}  
} 4\SBf\ c  
) wo2GF  
Sb9=$0%\  
/* f(s3TLM  
**SiteInfoBean.java K-k.=6mS  
*/ ],}afa!A  
package NetFox; wt=>{JM  
E(3+o\w  
D)ne *},  
public class SiteInfoBean { 6O@ ^`T  
m#'rI=}!  
Q1I_=fT  
private String sSiteURL; //Site's URL *5_ 8\7d  
private String sFilePath; //Saved File's Path y_4krY|Zx  
private String sFileName; //Saved File's Name #JR,C -w  
private int nSplitter; //Count of Splited Downloading File &c?hJ8"  
vWi. []  
Z0 IxYEp  
public SiteInfoBean() 8xpYQ<cax  
{//nSplitter的缺省值为5 NRuG?^/}d  
//default value of nSplitter is 5 #[0\=B -  
this("","","",5); BOiz ~h6  
} )C01f ZhD  
L8w76|  
E,D:D3O  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) U>_\  
{ ,dj* p ,J  
sSiteURL= sURL; 6n6VEwYj  
sFilePath = sPath; /mB Beg^a  
sFileName = sName; BXK::M+  
this.nSplitter = nSpiltter; Ril21o! j  
&Wz`>qYL*  
BUA6(  
} n:^"[Le  
zhX`~){N6  
HMS9y%zl/  
public String getSSiteURL() :OQ:@Yk  
{ $,QpSK`9i  
return sSiteURL; E4v_2Q -w  
} #u<o EDQ  
51ajE2+X&  
,F`KQ )\"  
public void setSSiteURL(String value) |`Oa/\U  
{ R|)2Dg  
sSiteURL = value; 6`4W,  
} x#j\"$dla  
e9Ul A  
Il^ \3T+  
public String getSFilePath() BvZ^^IUb  
{ <` p75B  
return sFilePath; APtselC  
} *e-ptgO  
,y8I)+  
<jRFN&"h}  
public void setSFilePath(String value) 6mF{ImbRbS  
{ +{C9uY)$vf  
sFilePath = value; Mi/ &$" =  
} ]Ic?:lKN  
V^`?8P8d  
4$?w D <  
public String getSFileName() |:(23O  
{ :B*vkwT  
return sFileName; =(|xU?OL  
} C7jc6(> m  
JwI`"$ > w  
;la#Vf:]  
public void setSFileName(String value) s7.p$r  
{ Ff Yd+]+?  
sFileName = value; 8R)D! 7[l  
} 3m43nJ.~  
"'F;lzq  
0Y6q$h>4  
public int getNSplitter() gP %|:"  
{ DD@)z0W  
return nSplitter; O+E1M=R6h  
} S}m$,<x  
1(%>`=R8  
@Ge>i5q  
public void setNSplitter(int nCount) oxMUW<gYd  
{ aW=By)S!Y  
nSplitter = nCount; kh<pLI>$h  
} yWv<A^C &  
} +w k]iH  
h5&/hBN  
%su}Ru  
/* L8bI0a]r"*  
**Utility.java {HIR>])o  
*/ EREolCASb  
package NetFox; +-H}s`  
Gq0]m  
@@%i( >4Z  
public class Utility { 83  i1  
Z@uTkqG)  
%qS]NC  
public Utility() bSrRsgKvT  
{ B=Zl&1  
lJ:M^.Em0  
A[^qq UL'  
} jF38kj3O7  
c?!YFm  
//线程睡眠 /lS+J(I  
public static void sleep(int nSecond) kfqpI  
{ e~+(7_2  
try{ =mHkXHE~:  
Thread.sleep(nSecond); E7X!cm/2<  
} m/YH^N0  
catch(Exception e) >:F,-cx<  
{ VG<Hw{ c3r  
e.printStackTrace (); @cuD8<\i  
} Ka]J^w;a  
} $5TepH0D  
;m@1Ec@* p  
//日志 2SDh0F  
public static void log(String sMsg) ~!nLbK2  
{ kgbobolA  
System.err.println(sMsg); Y{k>*: Ax_  
} HYjMNj0  
b&lN%+%}  
eeW' [  
public static void log(int sMsg) L bJtpwz>z  
{ 0$eyT-:d  
System.err.println(sMsg); ~9JW#HHzn  
} |'V DI]p&  
} O!+nF]V4f  
L@{!r=%_>  
lQV|U;~D  
/* _ yfdj[Ot`  
**TestMethod.java X5uS>V%/  
*/ ] vC=.&]  
package NetFox; "wA0 LH_  
 20I4r  
a'@-"qk  
public class TestMethod { $uEJn&n7}  
Xw7{R  
^ckj3Y#;  
public TestMethod() )t|^Nuj8  
{ ///xx/weblogic60b2_win.exe iD>G!\&  
try{ T)WZ_bR  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Y]C; T  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); hc-lzYS  
SiteFileFetch fileFetch = new SiteFileFetch(bean); /635B*g  
fileFetch.start(); 33Ssylno  
} #/ OUGeJ  
catch(Exception e){e.printStackTrace ();} |h5kg<Zgo  
I3Lg?bZ  
\\=.6cg<K  
} 6( >3P  
Dn~Z SrJ  
 f>.4-a?  
public static void main(String[] args) `WH[DQ  
{ q1YLq(e  
new TestMethod(); oi7 3YOB  
} j((hqJr  
} Y)$52m5rM  
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