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http断点续传简单实现(java)

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/* }Ec"&  
**SiteFileFetch.java >u[ln@ l  
*/ YR#1[fe*_  
package NetFox; 0M.[) @  
import java.io.*; ZS;kCdL   
import java.net.*; 8\_,Y ji  
AG=1TZI"  
0+h?Bk  
public class SiteFileFetch extends Thread { %uMsXa  
y[eNM6p  
M,lu)~H  
SiteInfoBean siteInfoBean = null; //文件信息Bean y5 +&P  
long[] nStartPos; //开始位置 -v&srd^  
long[] nEndPos; //结束位置 (#BA{9T,^  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 6?~pjMV  
long nFileLength; //文件长度 Fm{y.URo  
boolean bFirst = true; //是否第一次取文件 | mX8fRh  
boolean bStop = false; //停止标志 C*<LVW{P  
File tmpFile; //文件下载的临时信息 |a3b2x,  
DataOutputStream output; //输出到文件的输出流 }e w?{  
_"TG:RP  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) =]Bm>67"  
public SiteFileFetch(SiteInfoBean bean) throws IOException =^}2 /vA  
{ u^9,u/gj  
siteInfoBean = bean; \hX^Cn=6  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); evP`&23tP  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); CjCnh7tm  
if(tmpFile.exists ()) #SOe &W5  
{ 4QDzG~N4)|  
bFirst = false; 9`b3=&i\  
read_nPos(); .!! yj,bQz  
} sk/ Mh8z  
else 3M`J.>  
{ ea/6$f9^  
nStartPos = new long[bean.getNSplitter()]; yK;I<8+>_  
nEndPos = new long[bean.getNSplitter()]; X} 8U-N6)  
} $S/ 8T  
D':A-E  
*n\qV*|6bI  
'ZZ/:MvQa  
} U)6JJv  
]5CFL$_Q{  
dY^~^<{Lj  
public void run() MDt4KD+bZ  
{ .d,Zx  
//获得文件长度 To95WG7G  
//分割文件 2Ev,dWV  
//实例FileSplitterFetch +!wc(N[(2  
//启动FileSplitterFetch线程 xDS9gGr  
//等待子线程返回 yuq E  
try{ <Do89  
if(bFirst) vF 1$$7k  
{ ,'}ZcN2)  
nFileLength = getFileSize(); wz57.e!Me=  
if(nFileLength == -1) sy?W\(x  
{ fC[gu$f][  
System.err.println("File Length is not known!"); CJ>=odK[  
} O jmz/W  
else if(nFileLength == -2) %G*D0pE  
{ qK pU.rP  
System.err.println("File is not access!"); oj,  
} EWi@1PAZK  
else OduTg^R  
{ jTJ[2WaS  
for(int i=0;i<nStartPos.length;i++) sh RvwE[  
{ r}w 9?s^rB  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); {zcjTJ=Zt8  
} . j },  
for(int i=0;i<nEndPos.length-1;i++) hB4.tMgZ  
{ bBf+z7iyc  
nEndPos = nStartPos[i+1]; ;DOz92X94  
} TfOZ>uR"g  
nEndPos[nEndPos.length-1] = nFileLength; %]` WsG  
} pD9c%P  
} +J}M$e Q  
 E7,\s   
lPQH_+)Z"  
//启动子线程 X,b} d#\  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g o@}r<B$  
for(int i=0;i<nStartPos.length;i++) t+VPX2  
{ _e W*  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <f%9w]  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ZL Aq8X  
nStartPos,nEndPos,i); 3 ren1   
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U7N<!6  
fileSplitterFetch.start(); HD>{UU?  
} aap:~F{]X  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i8]r }a  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !WmpnPr1  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9z?F_=PB!  
nEndPos = " + nFileLength); @9L9c  
// fileSplitterFetch[nPos.length-1].start(); k dqH36&<  
@ NF8?>!  
Z'~5L_.]Ai  
//等待子线程结束 &*}S 0  
//int count = 0; pfG:P rZ  
//是否结束while循环 YY9q'x,w  
boolean breakWhile = false; (.cT<(TB  
UTz;Sw?~hw  
U8d  wb  
while(!bStop) S70ERRk  
{ Co M8  
write_nPos(); l40$}!!<  
Utility.sleep(500); %2{E'^#)p-  
breakWhile = true; GZ%R fKyQ  
hf '3yEm  
2+'&||h  
for(int i=0;i<nStartPos.length;i++) 5"sF#Y&  
{ ifkA3]  
if(!fileSplitterFetch.bDownOver) 0-FbV,:;  
{ _i&\G}mrC  
breakWhile = false; mnePm{  
break; $T6<9cB@  
} >&TktQO_T  
} al2v1.Y}  
if(breakWhile) >wn&+%i&  
break; aCanDMcBnq  
,/KHKLY7  
]Vubz54  
//count++; _^B+Xo@E-  
//if(count>4)  _R ]1J0  
// siteStop(); REJ}T:  
} .F]6uXd  
HZm44y$/  
1yo@CaW[\  
System.err.println("文件下载结束!"); * PZ=$>r  
} # ;9KDt@  
catch(Exception e){e.printStackTrace ();} H/b(dbs  
} yP@= x!$  
k$hWR;U  
m=R4A4Y7  
//获得文件长度 U> >J_2  
public long getFileSize() 1osI~oNZ  
{ @ZmpcoDI  
int nFileLength = -1; 3|A"CU/z@  
try{ )z aMycW  
URL url = new URL(siteInfoBean.getSSiteURL()); Vq*p?cF .  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ZE :oK   
httpConnection.setRequestProperty("User-Agent","NetFox"); Deam%)bXM]  
au8) G_A  
2XE4w# [j  
int responseCode=httpConnection.getResponseCode(); r"n)I$  
if(responseCode>=400) h'bxgIl'`  
{ @/9> /?JP  
processErrorCode(responseCode); 8E" .y$AW  
return -2; //-2 represent access is error a; "+Py  
} 27MgwX NQ  
~6OdPD  
NENbr$,G  
String sHeader; {\%x{  
GVg0)}  
R(:q^?  
for(int i=1;;i++) r1[0#5kJ;J  
{ 2]7nw1&  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); KT8Fn+  
//Utility.log(in.readLine()); 4-TM3Cw`d&  
sHeader=httpConnection.getHeaderFieldKey(i); }SYvGp{J,  
if(sHeader!=null) 8mV35A7l  
{ F 4k`x/ak  
if(sHeader.equals("Content-Length")) "];19]x6q  
{ ie_wJ=s  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #):FXB$a  
break; /g_}5s-Z  
} ^v,^.>P  
} 0uZHH  
else Di&tm1R1  
break; 2sXWeiJy;  
} )'qZ6%  
} s^ 6S{XJ  
catch(IOException e){e.printStackTrace ();} %9M_ * ]  
catch(Exception e){e.printStackTrace ();} WB= gN:?  
S]<Hx_[}  
.rS0zU  
Utility.log(nFileLength); E;+3VJ+F"  
<$UY{"?  
O|8p #  
return nFileLength; Q4UaqiL  
} !7_Q_h',  
{AB0 PM;-  
|=SaI%%Be  
//保存下载信息(文件指针位置) ua2SW(C@  
private void write_nPos() 1X=}  
{ Jo2:0<VL  
try{ s]}P jh8  
output = new DataOutputStream(new FileOutputStream(tmpFile)); E*CY/F I_  
output.writeInt(nStartPos.length); :HwB+Bjy  
for(int i=0;i<nStartPos.length;i++) E")82I  
{ GU_R6Wt+  
// output.writeLong(nPos); -{ZRk[>Z  
output.writeLong(fileSplitterFetch.nStartPos); VG)kPKoi  
output.writeLong(fileSplitterFetch.nEndPos); .aNy)Yu8  
} l2$6ojpo  
output.close(); O)W1.]GMbf  
} dC)@v]#h  
catch(IOException e){e.printStackTrace ();} GUMO;rZs  
catch(Exception e){e.printStackTrace ();} ? -6oh~W<  
} z0c_&@uj*  
8)T.[AP  
>R :Bkf-  
//读取保存的下载信息(文件指针位置) O[$ &]>x]]  
private void read_nPos() './s'!Lj  
{ (A?/D!y  
try{ wVp  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); edA.Va|0  
int nCount = input.readInt(); :dB6/@f W  
nStartPos = new long[nCount]; ZXp=QH+f  
nEndPos = new long[nCount]; 40mgB4I  
for(int i=0;i<nStartPos.length;i++) zU]95I  
{ U"/":w ~  
nStartPos = input.readLong(); >8EIm  
nEndPos = input.readLong(); yw2sK7  
} \=i>}Sg  
input.close(); @*!8  
} 4R.rSsAH  
catch(IOException e){e.printStackTrace ();} %gmf  
catch(Exception e){e.printStackTrace ();} Ioj F/  
} /JJU-A(  
(oxe'\  
A=Dzd/CUO  
private void processErrorCode(int nErrorCode) HPT$)NeNc  
{ A[^fG_l4  
System.err.println("Error Code : " + nErrorCode); ?9.SwIxU&  
} aO6w :IO  
r;SA1n#  
d'q,:="c  
//停止文件下载 # sm>;+J  
public void siteStop() |h4aJv  
{ >}Fe9Y.o  
bStop = true; 6f(K'v  
for(int i=0;i<nStartPos.length;i++) xV}-[W5sr'  
fileSplitterFetch.splitterStop(); 6o!+E@V b  
?o?~Df&  
"1yXOy^2  
} \$W>@w0  
} n}}$-xl  
//负责部分文件的抓取 L^!E4[ ^4  
**FileSplitterFetch.java a}EO7tcg,  
*/ 1UT&kD!si  
package NetFox; : OQx;>'  
 1ti+ Q0~  
$0=f9+@5  
import java.io.*; Z2!O)8  
import java.net.*; }y;s(4  
%9C_p]P*  
ncjtv"2R  
public class FileSplitterFetch extends Thread { z^'3f!:3  
:  *k   
?@!dc6   
String sURL; //File URL  ]Vuq)#  
long nStartPos; //File Snippet Start Position cA m>f[  
long nEndPos; //File Snippet End Position rzsAnLxo  
int nThreadID; //Thread's ID *#\da]"{  
boolean bDownOver = false; //Downing is over rI23e[  
boolean bStop = false; //Stop identical {d|e@`"T  
FileAccessI fileAccessI = null; //File Access interface 2guWWFS  
%L,mj  
L/t'|<m  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException BUvE~l.,|  
{ $t}t'uJ  
this.sURL = sURL; __O@w.  
this.nStartPos = nStart; 8 6y)+h`  
this.nEndPos = nEnd; eEl}.W}  
nThreadID = id; ?H3Ls~R  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 D;*P'%_Z  
} +`'=K ;{U  
2 ,RO  
|L%}@e Vw_  
public void run() `v) :|Q  
{ ^}8qPBz  
while(nStartPos < nEndPos && !bStop) ;n`SF~CU  
{ \W:~;GMeD  
LpN_s#  
rY yB"|  
try{ Vz[tgb]-  
URL url = new URL(sURL); }04 EM  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G6@XRib3  
httpConnection.setRequestProperty("User-Agent","NetFox"); )i|0Ubn[|  
String sProperty = "bytes="+nStartPos+"-"; l/ufu[x!a  
httpConnection.setRequestProperty("RANGE",sProperty); 0&wbGbg(W  
Utility.log(sProperty); )"KKBil0  
l=4lhFG,Mk  
qJN!L))  
InputStream input = httpConnection.getInputStream(); Ps<;DE\$f4  
//logResponseHead(httpConnection); ^V,?n@c!  
JiH^N!  
v{tw;Z#  
byte[] b = new byte[1024]; ~*NG~Kn"s  
int nRead; 2nz^%pLT  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) IqD;*  
{ ^6g^ Q*"  
nStartPos += fileAccessI.write(b,0,nRead); .0 }eg$d  
//if(nThreadID == 1) Q &~|P}  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ' m^nKG$"  
} pg0Sq9qCN  
*,az`U  
Wl?0|{W  
Utility.log("Thread " + nThreadID + " is over!"); T%q@jv{c  
bDownOver = true; xNAX)v3Z  
//nPos = fileAccessI.write (b,0,nRead); we?# Dui  
} ,v\^efc:%  
catch(Exception e){e.printStackTrace ();} |f67aN  
} x#)CH}J  
} GoSdo  
f N_8HP6&  
rD_\NgVAs  
//打印回应的头信息 1/\JJ\  
public void logResponseHead(HttpURLConnection con) C6` Tck!  
{ UmEc")3  
for(int i=1;;i++) b;xn0sDn#  
{ s]X0}"cz  
String header=con.getHeaderFieldKey(i); r{g8CIwGQ  
if(header!=null) 6~b)Hc/  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^GL>xlZ(  
Utility.log(header+" : "+con.getHeaderField(header)); ?cur}`  
else L*(Sh2=_  
break; H;w8[ImK  
} FHOF 6}if  
} X iW~? *Z  
X\Gbs=sf6  
Gv\39+9 =  
public void splitterStop() i0q<,VSl$_  
{ lD9QS ;  
bStop = true; 0Ba*"/U]t~  
} oU`{6 ~;  
2p|ed=ly%  
(pv6V2i  
} y?Cq{(  
2r^G;,{  
;X;q8J^_K_  
/* {J~VB~('  
**FileAccess.java yt+d f0l  
*//文件访问(定位,写) [x[ nTIg  
package NetFox; ;)Fc@OXN>  
import java.io.*; W @ ?*~  
Fswr @du  
_ ci8!PP  
public class FileAccessI implements Serializable{ C.`!?CW  
*N65B#  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 r7FFZNs!  
RandomAccessFile oSavedFile; JavSR1_  
long nPos; IRG-H!FV  
Wj I NY  
s:zz 8oN  
public FileAccessI() throws IOException 5}Z_A?gy  
{ 6<SX%Bc~  
this("",0); 2 Q}^<^r  
} '5etZ!:  
1fMl8[!JLu  
XMlcY;W  
public FileAccessI(String sName,long nPos) throws IOException It#T\fU  
{ 3]rd!Gp=*  
oSavedFile = new RandomAccessFile(sName,"rw"); S;tv4JY  
this.nPos = nPos; lvp8{]I<  
oSavedFile.seek(nPos); >Q#\X=a>  
} zvOSQxGQ  
IeT1Jwe  
]@A31P4t|  
public synchronized int write(byte[] b,int nStart,int nLen) }cO}H2m  
{ ~0V,B1a  
int n = -1; ,Pj UlcO_  
try{ I?OnEw  
oSavedFile.write(b,nStart,nLen); 2fFGS.l  
n = nLen; (@i2a  
} ItxC}qT  
catch(IOException e) tlyDXB~+  
{ dV7~C@k6k8  
e.printStackTrace (); v5A8"&Jr  
} 7N8a48$8  
D` abVf  
,V`[;~49  
return n; G[lNgVbU@  
} fI }v}L^  
P$i d?  
w,VUWja  
} 1kczlTF  
d>hLnz1O  
krecUpo  
/* DAVgP7h'  
**SiteInfoBean.java ^3lEfI<pBm  
*/ !Ct'H1J-  
package NetFox; 94'0X  
D:#e;K  
i1 ^#TC$x  
public class SiteInfoBean { T{4Ru6[  
Sp\ 7  
q~6((pWi|  
private String sSiteURL; //Site's URL rvETt  
private String sFilePath; //Saved File's Path I%tJLdL  
private String sFileName; //Saved File's Name &Ef_p-e-P  
private int nSplitter; //Count of Splited Downloading File )^]1j$N=3  
Uu(FFd~3  
[`U9  
public SiteInfoBean() gaVQ3NqF  
{//nSplitter的缺省值为5 w ;]~2$  
//default value of nSplitter is 5 ] :n! \G  
this("","","",5); hWAZP=H  
} "!z9UiA  
IiB"F<&[j{  
'w`3( ':=  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) M2rgB%W)m  
{ o 4cqLM u  
sSiteURL= sURL; dZ{yNh.]  
sFilePath = sPath; bFwc>  
sFileName = sName; {N`<TH PP  
this.nSplitter = nSpiltter; ~]C m  
sHf.xc  
yQdoy^d/4  
} gF8n{b  
-eQ70BXvB  
[.LbX`K:  
public String getSSiteURL() , Vr'F  
{ b5Vn_;V*  
return sSiteURL; D&nVkZP>  
} |^T?5=&Kt  
m\;@~o'k  
f ,WAl\  
public void setSSiteURL(String value) ~-zch=+u  
{ *WK0dn  
sSiteURL = value; 4@1C$|k  
} @`H47@e  
Hribk[99  
>'e(|P4  
public String getSFilePath() .F@0`*#rE~  
{ :vRUb>z  
return sFilePath; 0pl |  
} 4pC.mRu 0  
7FvtWE*  
VmTPE5d  
public void setSFilePath(String value) uwhb-.w  
{ $G .ws  
sFilePath = value; -$+`v<[r  
} iw?*Wp25  
3lT>C'qq  
XXA1%Lw%  
public String getSFileName() 59Lmv &s  
{ 9Bw.Ih[Z  
return sFileName; xji2#S%  
} @WfX{485  
1GI/gc\  
 k.("<)  
public void setSFileName(String value) *9I/h~I  
{ <{k r5<  
sFileName = value; kZJ.G  
} 8e*1L:oB!  
h4lrt  
m[%*O#_  
public int getNSplitter() rA6lyzJ  
{ A0`#n|(Ad!  
return nSplitter; Fg<rz&MR  
} UqEpeLK  
:qL1jnR^  
;8J+Q0V  
public void setNSplitter(int nCount) - }2AXP2q  
{ @ZTsl ?  
nSplitter = nCount; `/\Z{j0_  
} DU=rsePWE  
} eh5j  
568qdD`PS  
2c4x=%  
/* +8~C&K:  
**Utility.java 4g}'/  
*/ dyN Kok#  
package NetFox; ?O.1HEr  
yo@S.7[/  
[d}AlG!  
public class Utility { %9lx)w  
SFQYrY  
6x8P}?  
public Utility() ~L7@,d:  
{ E3==gYCe*  
~qj09  
@.SuHd  
} 1w/Ur'8we  
D`C#O 7.N  
//线程睡眠 hEv}g  
public static void sleep(int nSecond) D<:J6W7]  
{ ::eYd23  
try{ : ZWKrnG  
Thread.sleep(nSecond); cTQ]0<9:e  
} \WN ,.  
catch(Exception e) y+g01z  
{ W`2Xn?g  
e.printStackTrace (); eK=<a<tx  
} YN>k5\M_v  
} MrGq{,6C  
a/v!W@Zz}  
//日志 X:1&Pdi  
public static void log(String sMsg) }aC@ov]2  
{ j68_3zpl  
System.err.println(sMsg); ;"N4Yflz  
} DbH"e  
. vJlTg  
K,' v{wSr  
public static void log(int sMsg) OqcM3#  
{ E)}& p\{E  
System.err.println(sMsg); n^P~]1i   
} /-v6jiM  
} |{en) {:  
FC BsC#  
 5gZ6H/.  
/* ]:X# w0UR  
**TestMethod.java <*'%Xgm  
*/ $wBF'|eU  
package NetFox; znxP.=GB   
@V>BG8Y  
jFr[T  
public class TestMethod { d%wy@h  
bh&Wy<Y  
 <RaM@E  
public TestMethod() ZJ Ke}F`l  
{ ///xx/weblogic60b2_win.exe N ">4I)  
try{ eGF+@)K1"  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); psaPrE  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;)'@kzi  
SiteFileFetch fileFetch = new SiteFileFetch(bean); a6<UMJ  
fileFetch.start(); & uMx*TTY  
} d)yu`U  
catch(Exception e){e.printStackTrace ();} iXsX@ S^F  
6";ew:Ih^  
"7X[@xX@  
} {k"t`uo_  
ah9P C7[  
uihU)]+@t/  
public static void main(String[] args) 7kDqgod^A  
{ 1](PuQm7+  
new TestMethod(); "AcC\iq  
} ??u*qO:p  
} Wp2$L-T&$  
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