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http断点续传简单实现(java)

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/* Kcsje_I-M  
**SiteFileFetch.java ~ Y4H)r  
*/ QI0ARdS  
package NetFox; z]gxkol\  
import java.io.*; E4T?8TO$o%  
import java.net.*; L((z;y>q|  
wAF>C[<\  
96}/;e]@  
public class SiteFileFetch extends Thread { `w[0q?}"`  
FGy7KVR  
AWh{dM  
SiteInfoBean siteInfoBean = null; //文件信息Bean m&Ms[X  
long[] nStartPos; //开始位置 xZGR<+t  
long[] nEndPos; //结束位置 6X7r=w  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 }{bO ~L7  
long nFileLength; //文件长度 PcM:0(,G  
boolean bFirst = true; //是否第一次取文件 n!ea)+^  
boolean bStop = false; //停止标志 r1}7Q7-z  
File tmpFile; //文件下载的临时信息 u32wS$*8  
DataOutputStream output; //输出到文件的输出流 44kY[jhf  
lY?TF  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 1YAy\F~`.  
public SiteFileFetch(SiteInfoBean bean) throws IOException 87YT;Z;U&  
{ ?rk3oa-  
siteInfoBean = bean; unSF;S<  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Q\m"n^XN  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); xDRK^nmC  
if(tmpFile.exists ()) >J.a, !  
{ E+ JGqk  
bFirst = false; Y0&w;P  
read_nPos(); ^%IKlj- E  
} X H{5E4P  
else ,y:q]PR  
{ yoGE#+|7^  
nStartPos = new long[bean.getNSplitter()]; vQc>jmS+n  
nEndPos = new long[bean.getNSplitter()]; ]9R?2{"K  
} kYPowM  
YRW<n9=3  
jM2gu~  
dWI/X  
} 4w2V["?X1  
f>#\'+l'  
oYlq1MB?  
public void run() gA" =so  
{ UrN$nhH  
//获得文件长度 0t/S_Q  
//分割文件 SY>N-fW\H:  
//实例FileSplitterFetch nUd(@@%m  
//启动FileSplitterFetch线程 =1VY/sv  
//等待子线程返回 1?E\2t&K  
try{ goRoi\z $  
if(bFirst) r/:9j(yxr  
{ %QwMB`x  
nFileLength = getFileSize(); } ..}]J;To  
if(nFileLength == -1) D dt9`j  
{ 0kmVP~K  
System.err.println("File Length is not known!"); ~4XJ" d3L  
} n)$ q*IN"  
else if(nFileLength == -2) @^k$`W;  
{ :L*CL 8m  
System.err.println("File is not access!"); r[EN`AxDb  
} <0JW[m  
else <9\_b 6  
{ zh*NRN  
for(int i=0;i<nStartPos.length;i++) <:q]t6]$  
{ JOenVepQ,  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); J5@_OIc1y  
} mEyZ<U9  
for(int i=0;i<nEndPos.length-1;i++) tnRq?  
{ Z|'tw^0e5  
nEndPos = nStartPos[i+1]; e0v&wSi  
} BCsW03sQ  
nEndPos[nEndPos.length-1] = nFileLength; F'pD_d9]e  
} _$i9Tk  
} EBK\.[  
zVl(?b&CF  
u^!-Z)W  
//启动子线程 y])xP%q2 O  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; dYf Vox;  
for(int i=0;i<nStartPos.length;i++) ]7h&ZF  
{ A n/)|B4  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZLE4 XB]  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), s49 AF  
nStartPos,nEndPos,i); ~|l>bf  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lYQcQ*-  
fileSplitterFetch.start(); > { fX;l  
} mR8&9]g&  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,h8)5Mj/J  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); o#%2N+w  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 2MtaOG2l&q  
nEndPos = " + nFileLength); 5x=tOR/h  
// fileSplitterFetch[nPos.length-1].start(); sI9~TZ :  
r IS \#j  
~y B[}BPf  
//等待子线程结束 pZjyzH{~  
//int count = 0; }KS[(Q  
//是否结束while循环 0DS<(  
boolean breakWhile = false; UL"Jwq D  
-2% [ ]  
KZ/}Iy>As  
while(!bStop) K<Iz5+oD  
{ :rk]o*  
write_nPos(); q;>'jHh  
Utility.sleep(500); Fc 5g~T  
breakWhile = true; uysGOyi<u  
crZ\:LeJ  
;I5HMc_a"  
for(int i=0;i<nStartPos.length;i++) Dc #iM0  
{ ZVK;m1?'  
if(!fileSplitterFetch.bDownOver) Er~5\9,/<]  
{ ;v8,r#4  
breakWhile = false; BuK82   
break; J~n{gT<L  
} 'T+3tGCy+  
} P(A%z2Ql  
if(breakWhile) O3Ks|%1  
break; (MJu3t @  
urXM}^  
?\ho9nyK  
//count++; |W\CV0L2  
//if(count>4) - Nplx  
// siteStop(); }tc,3> /  
} pX6OhwkTK  
^[^uDE <  
=0x[Sa$&,  
System.err.println("文件下载结束!"); )0qXZ gs  
} VPtA %1  
catch(Exception e){e.printStackTrace ();} *K-,<hJ#L  
} dIIsO{Zqv  
"F)7!e  
)M'#l<9B  
//获得文件长度 }{]{`\  
public long getFileSize() w;>]L.n  
{ Dve5Ml-  
int nFileLength = -1; "QGP]F  
try{ fv<($[0  
URL url = new URL(siteInfoBean.getSSiteURL()); 9Tjvc!4_b  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9dy"Y~c  
httpConnection.setRequestProperty("User-Agent","NetFox"); |l7e*$j  
U:YT>U1Z  
2JtGS-t  
int responseCode=httpConnection.getResponseCode(); ed>_=i  
if(responseCode>=400) M7!&gFv8  
{ (w"zI!  
processErrorCode(responseCode); d3^LalAp  
return -2; //-2 represent access is error 63-`3R?;  
} #Cbn"iYee  
Z-]d_Y~m4  
+,c;Dff  
String sHeader; =2->1<!x6<  
>/$Q:92T  
n'%*vdHK m  
for(int i=1;;i++) |Q.?<T:wt=  
{ /$I&D}uR`  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _%Mu{Ni&  
//Utility.log(in.readLine()); &$vDC M4  
sHeader=httpConnection.getHeaderFieldKey(i); }Ct_i'Ow  
if(sHeader!=null) p5G O@^i  
{ /Hx%gKU  
if(sHeader.equals("Content-Length")) /M B0%6m  
{ h/eKVRGs"  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); AB}Qd\  
break; X+bLLW>&  
} 6Y\9h)1Jo  
} HT kce,dQ  
else 6q6&N'We  
break; `=%[  
} ~''qd\.f$  
}  X-~Q  
catch(IOException e){e.printStackTrace ();} ^'v6 ,*:4  
catch(Exception e){e.printStackTrace ();} ^ /:]HG  
8>Ervi`  
v%86JUlK.  
Utility.log(nFileLength); +z("'Cv  
P,D >gxl  
*w> /vu  
return nFileLength; BjOrQAO  
} 83;1L:}`  
>2>xr"  
w&:h^u  
//保存下载信息(文件指针位置) E62VuX  
private void write_nPos() ,7/un8:%c  
{ jwAO{.}T1r  
try{ p B?a5jpA  
output = new DataOutputStream(new FileOutputStream(tmpFile)); OkA-=M)RI:  
output.writeInt(nStartPos.length); +zz9u?2C`  
for(int i=0;i<nStartPos.length;i++) >JCSOI  
{ Odw SNG  
// output.writeLong(nPos); @RbAC*Y]g  
output.writeLong(fileSplitterFetch.nStartPos); ~~ )&? \N  
output.writeLong(fileSplitterFetch.nEndPos); >,hJ5-9  
} XD%?'uUQ_  
output.close(); g<}EL[9  
} P{QRmEE  
catch(IOException e){e.printStackTrace ();} nb0<.ICF%R  
catch(Exception e){e.printStackTrace ();} 5g/^wKhKG  
} a[Txd=b  
dA\>z[n=  
rYN`u  
//读取保存的下载信息(文件指针位置) ot(|t4^  
private void read_nPos() LUS7-~:F  
{ 90I)"vfW5  
try{ '>'h7F=tY  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); EkWe6m  
int nCount = input.readInt(); Qpf BM  
nStartPos = new long[nCount]; 3<fJ5-z|-  
nEndPos = new long[nCount]; Ob0=ZW`+&  
for(int i=0;i<nStartPos.length;i++) a; /4 ht  
{ ~3f#cEP>d}  
nStartPos = input.readLong(); [>Q{70 c[  
nEndPos = input.readLong(); Q 7B)t;^  
} &\C vrxa  
input.close(); EB@!?=0x  
} i&.F}bEi  
catch(IOException e){e.printStackTrace ();} 4B (*{  
catch(Exception e){e.printStackTrace ();} K%Q^2"Eb0  
} Mt@K01MI%  
iVXR=A\er  
WMh'<'w N_  
private void processErrorCode(int nErrorCode) 0Xk;X1Xl  
{ >+,1@R  
System.err.println("Error Code : " + nErrorCode); R&PQ[Xc  
} ufEt"P-X.  
']+H P9i$  
,u~\$ Az6  
//停止文件下载 1T}|c;fc  
public void siteStop() +".&A#wU  
{ P]dDTh~e~  
bStop = true; uz'beE  
for(int i=0;i<nStartPos.length;i++) |W:kzTT-T  
fileSplitterFetch.splitterStop(); ua7I K~8l  
~}4H=[Zu  
S$muV9z2=  
} mpr["C"l  
} :GL|:  
//负责部分文件的抓取 \O7,CxD2  
**FileSplitterFetch.java 2(`2f  
*/ @J" }~Y  
package NetFox; R+!2 j  
#Kn7 xn[  
bmT  J  
import java.io.*; mO> [kb"V'  
import java.net.*; H~Q UN  
IFpmf0;^  
:VLuI  
public class FileSplitterFetch extends Thread { rD$7;  
^D vaT9s  
i Cv &<C@  
String sURL; //File URL ^T^U:Zdq  
long nStartPos; //File Snippet Start Position {p6",d."N&  
long nEndPos; //File Snippet End Position #/1A:ig  
int nThreadID; //Thread's ID TU[f"!z^  
boolean bDownOver = false; //Downing is over S@_@hFV jd  
boolean bStop = false; //Stop identical WYaDN:kZf  
FileAccessI fileAccessI = null; //File Access interface Y>%A*|U%  
X4%*&L  
O8dDoP\F2  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException I X\&lV  
{ ?>lmLz!e  
this.sURL = sURL; f<kL}B+,Og  
this.nStartPos = nStart; <;U"D.'  
this.nEndPos = nEnd; cpE&Fba}"  
nThreadID = id; `5GJ,*{z  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 uLL#(bhDr  
} Tb{,WUJg2  
kN>d5q9b%X  
7Jc=`Zm'  
public void run() g3x192f  
{ RJtSHiM2  
while(nStartPos < nEndPos && !bStop) 6;(Slkv  
{ \DGm[/P  
2M1yw "  
!L3Bvb;Q  
try{ Y|B/(  
URL url = new URL(sURL); o_\b{<^I  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6[qRb+ds  
httpConnection.setRequestProperty("User-Agent","NetFox"); N?87Bd  
String sProperty = "bytes="+nStartPos+"-"; Jw {:1  
httpConnection.setRequestProperty("RANGE",sProperty); @ZX{q~g!  
Utility.log(sProperty); VK`b'U &l"  
sBSBDjk[  
Yq5}r?N  
InputStream input = httpConnection.getInputStream(); sV[|op  
//logResponseHead(httpConnection); &BE[=& |  
s|{K?s  
"?avb`YU'  
byte[] b = new byte[1024]; uVisU%p  
int nRead; %FyB\IQ  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) f#X`e'1  
{ p1Lx\   
nStartPos += fileAccessI.write(b,0,nRead); EQ=Enw1[  
//if(nThreadID == 1) |: nuT$(  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :;??!V  
} J`"1DlH  
fDbs3"H Q  
d,D)>Y'h  
Utility.log("Thread " + nThreadID + " is over!"); E,C<ox4e  
bDownOver = true; eMh:T@SN  
//nPos = fileAccessI.write (b,0,nRead); cwpDad[Kx  
} 5~.\rcr%  
catch(Exception e){e.printStackTrace ();} *]Vx=7 D  
} ^i:%;oeG  
} Ke 'bH  
C2Y&qX,  
Wm3H6o*  
//打印回应的头信息 {z.}u5N  
public void logResponseHead(HttpURLConnection con) i [j`'.fj  
{ &Rn/ c}[{  
for(int i=1;;i++) I [e7Up  
{ MGmtA(  
String header=con.getHeaderFieldKey(i); c~C :"g.y  
if(header!=null) P, S9gG9  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4AF" +L  
Utility.log(header+" : "+con.getHeaderField(header)); f-{[ushj  
else IndNR:"g  
break; EO| kiC   
} h+$_:](PC  
} %F}`;>C3  
SH`"o  
<&+l;z  
public void splitterStop() Y[x ^59  
{ crhck'?0  
bStop = true; Zn9w1ev  
} I1}{7-_t  
%@BQv 4oJ  
]AHi$Xx  
} Tzk8y 7$[  
X2Lhb{ZHE  
}]n&"=Zk-  
/* {{<o1{_H  
**FileAccess.java !P:hf/l[B  
*//文件访问(定位,写) qC3 rHT]  
package NetFox; -<s?`Rnk  
import java.io.*; T`WFY  
pH"LZ7)DI0  
f}+G;a9Nj  
public class FileAccessI implements Serializable{ :+R ||q i  
:*oI"U*f  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }wv$ #H[  
RandomAccessFile oSavedFile; #lB[]2]N  
long nPos; PD/~@OsxU  
I&(cdKY z  
_nTjCN625  
public FileAccessI() throws IOException H%sQVE7m  
{ ^lQ-w|7(  
this("",0); B2,! 0Re  
} b(XhwkGVq  
GN~:rdd  
H}}t )H  
public FileAccessI(String sName,long nPos) throws IOException #Xn#e  
{ x?j&Jn_@w  
oSavedFile = new RandomAccessFile(sName,"rw"); eg,S(;VEt  
this.nPos = nPos; l YZHM,"  
oSavedFile.seek(nPos); > ZNL pJQ  
} f0^s*V+  
c}{e,t  
VKs$J)6  
public synchronized int write(byte[] b,int nStart,int nLen) UW>~C  
{ tSO F7N/<  
int n = -1; uZQ)A,#n;  
try{ 1-qQp.Wj  
oSavedFile.write(b,nStart,nLen); mS );bs  
n = nLen; hyTi':  
} p jrA:;  
catch(IOException e) E|5gKp-wJ  
{ ]#*@<T*[  
e.printStackTrace (); ~ R*6w($  
} TY88PXW  
|Y])|`_'G  
2cmqtlW"  
return n; [&zP$i&  
} i "-#1vy=  
+ATN2 o  
.:lzT"QXI  
} D<rjxP  
]&9f:5',  
Z v~ A9bB  
/* q,*IR*B:a  
**SiteInfoBean.java O=-|b kO  
*/ Mv9s  
package NetFox; H?aB8=)  
jn+0g:l  
"`3H0il;<  
public class SiteInfoBean { fB:M'A'  
p(U'Ydl~  
n&Al~-Q:^  
private String sSiteURL; //Site's URL kKjYMYT6  
private String sFilePath; //Saved File's Path 3Ys|M%N  
private String sFileName; //Saved File's Name pw$I~3OFd  
private int nSplitter; //Count of Splited Downloading File 'l;?P  
|YlUt~H>  
$[>wJXj3R  
public SiteInfoBean() vfo[<"  
{//nSplitter的缺省值为5 rVN|OLh  
//default value of nSplitter is 5 rSZWmns  
this("","","",5); 5Pr<%}[S^  
} 9Qkww&VEk  
ae^xuM?7  
N..u<06j/  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2`Pk@,:_  
{ Lc.7:r  
sSiteURL= sURL; ~ h:^Q  
sFilePath = sPath; i>rn!?b  
sFileName = sName; ^%<v| Y(X  
this.nSplitter = nSpiltter; ^L'K?o  
qM9GW`CKA  
f/ =0  
} ec3('}X  
):\ pD]e  
[XQNgSy?z  
public String getSSiteURL() )kd)v4#  
{ =-q)I[4#  
return sSiteURL; =djzE`)0  
} {#;6$dU;(  
cX&c%~  
cf j6I  
public void setSSiteURL(String value) T&S< 0  
{ .oe,# 1Qh{  
sSiteURL = value; R]r~TJ o  
} }U(^QB  
]>AW  
RSnK`N\9jb  
public String getSFilePath() Y0b.utR&  
{ <e=0J8V8,i  
return sFilePath; wWm#[f],?  
} vx ,yz+yP  
$]T7Iwk  
5(F!* 6i>  
public void setSFilePath(String value) kPxEGuL'  
{ 7v?Ygtv  
sFilePath = value; 2GD%=rP2]  
} J[B8sa  
PCU6E9~t2  
*".7O*jjV  
public String getSFileName() J]~3{Mi  
{ *U]f6Q<X  
return sFileName; ' Wi*[  
} xp39TiXJ*  
0qTa @y  
'Gc6ZSLM  
public void setSFileName(String value) w5[POo' 5  
{ Xr~r`bR=  
sFileName = value; o2.! G  
} Cr[#D$::`  
s9'iHe  
/|\`NARI  
public int getNSplitter() =]^* -f}J9  
{ svQDSif  
return nSplitter; "Fke(?X'  
} {66vdAu&h<  
~k J#IA  
?Cu$qE!h)[  
public void setNSplitter(int nCount) vw!i)JO8M  
{ XkNi 'GJf  
nSplitter = nCount; z* `81  
} ,fN iZ  
} O+e8}Tmm  
\ 0CGS  
`\qU.m0(j  
/* ypsCyDQK`  
**Utility.java MKH7d/x  
*/ '1mygplW  
package NetFox; &?9.Y,  
@9L%`=]b^  
WL7:22nSHa  
public class Utility { Jne)?Gt  
p*N+B o  
p]>bN  
public Utility() F6 UOo.L)I  
{ !",@,$  
 CZuxH  
YGNX+6Lz  
} zxj!ihs<  
2AlLcfAW  
//线程睡眠 cAL&>T  
public static void sleep(int nSecond) m\VJ=  
{ 3O]e  
try{ 6znm?s@~  
Thread.sleep(nSecond); 'LX=yL]I  
} [2 Rp.?  
catch(Exception e) crmnh4-  
{ S^n:O  
e.printStackTrace (); wF&\@H  
} !.F\v .  
} Pq`4Y K  
m t*v@'l.  
//日志 l"vT@ g|  
public static void log(String sMsg) foN;Q1?lS  
{ 't>Qj7vh0  
System.err.println(sMsg); iCc \p2p  
} *JDc1$H0  
!"1bV [^  
rKjQEO$yi  
public static void log(int sMsg) ;DGWUK.U[H  
{ vWgh?h/ot  
System.err.println(sMsg); R `'@$"  
} Rc6Rk!^  
} 7'<4'BGzl]  
WpvH} l r}  
X!"y>J  
/* :q= XE$%H  
**TestMethod.java ,= PDL  
*/ Mc\lzq8\ 1  
package NetFox; ;or> Sh7  
f.u{;W  
,%:`Ll t]$  
public class TestMethod { A8A+ImwO"  
uIba{9tM"P  
RJ-CWt [LG  
public TestMethod() *}0Q S@FN  
{ ///xx/weblogic60b2_win.exe p;'vOb  
try{ nU`;MW/^w  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >U}~Hv]  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); q`{.2yV  
SiteFileFetch fileFetch = new SiteFileFetch(bean); UjfB+=7I{L  
fileFetch.start(); O/5W-u  
} mki=.l$O  
catch(Exception e){e.printStackTrace ();} Kp99y  
9R E;50h  
WAQv4&xGM  
} BujWql  
pu^1s#g8w  
-ss2X  
public static void main(String[] args) Wd%j;glG  
{ h&Sl8$jVp  
new TestMethod(); >LNl8X:Cz*  
} weDv[b5i  
} \Z~m6;  
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