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http断点续传简单实现(java)

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/* F<oc Y0=9p  
**SiteFileFetch.java [,o5QH\Etq  
*/ 9*TS90>a  
package NetFox; ox\B3U%`p}  
import java.io.*; &W)+8N,L  
import java.net.*; [;IDTo!<>  
hDD~,/yVxs  
y5AXL5  
public class SiteFileFetch extends Thread { +%le/Pg@  
X~)V)'R  
\A3>c|  
SiteInfoBean siteInfoBean = null; //文件信息Bean x(3 I?#kE  
long[] nStartPos; //开始位置 x,w`OMQ}c  
long[] nEndPos; //结束位置 =FD`A#\C~  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ReB(T7Vk=  
long nFileLength; //文件长度 4Fr7jD,#k  
boolean bFirst = true; //是否第一次取文件  $`XN  
boolean bStop = false; //停止标志 FG;<`4mY  
File tmpFile; //文件下载的临时信息 B=Zukg1G  
DataOutputStream output; //输出到文件的输出流 hV>4D&<  
@cS1w'=  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) sx-Hw4.a"  
public SiteFileFetch(SiteInfoBean bean) throws IOException I"F .%re  
{ ><#2O  
siteInfoBean = bean; RP|>&I  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); uku}Mr"p  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); lEyG9Xvi  
if(tmpFile.exists ()) WK_y1(v>  
{ GEe 0@q#YA  
bFirst = false; m_E[bDON  
read_nPos(); ,3J`ftCV  
} _/N'I7g  
else 0x>/6 <<  
{ L&DF,fWsF&  
nStartPos = new long[bean.getNSplitter()]; G1?0Q_RN  
nEndPos = new long[bean.getNSplitter()]; I4o =6ts  
} ,>QMyI hv  
*b6I%MZn  
d Ik8TJ  
fOK+DT~  
} 9Ew:.&d  
Rekb?|{z  
p29yaM  
public void run() ,{uW8L  
{ 6HEqm>Yau  
//获得文件长度 Ha=_u+@  
//分割文件 d Y:|Ef|v(  
//实例FileSplitterFetch y} $ P,  
//启动FileSplitterFetch线程 KTLbqSS\  
//等待子线程返回 l?o-!M{  
try{ !Ig|m+  
if(bFirst) ##EB; Y  
{ v ]/OAH6D  
nFileLength = getFileSize(); )y%jLiQv  
if(nFileLength == -1) ]< s\V-y  
{ R%Ui6dCLo  
System.err.println("File Length is not known!"); `FzYvd"N  
} \ifK~?  
else if(nFileLength == -2) n2xLgK=  
{ Ss#@=:"P  
System.err.println("File is not access!"); |P,zGy  
} !^)wPmk  
else `?zg3GD_  
{ o[bE  
for(int i=0;i<nStartPos.length;i++) 96"yNqBf  
{ V9fGVDl;  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); +{")E)  
} <fC@KY>#  
for(int i=0;i<nEndPos.length-1;i++) S' (cqO}=F  
{ @)W(q5)}9"  
nEndPos = nStartPos[i+1]; .pS&0gBo\  
} PcHSm/d0e  
nEndPos[nEndPos.length-1] = nFileLength; ~7lTqY\  
} yqC Q24  
} e-CNQnO~  
X$7Oo^1;  
h&=O-5  
//启动子线程 GSMk\9SI  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Pl rkgS0J  
for(int i=0;i<nStartPos.length;i++) &v5G92  
{ g.B%#bfg  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^CZCZ,v  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }}^,7npU  
nStartPos,nEndPos,i); ID67?:%r  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Jv_.itc  
fileSplitterFetch.start(); B ~fSMB6h  
} Vq3gceo'0A  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !_CX2|  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); YCa@R!M*O  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", qP~WEcH`[  
nEndPos = " + nFileLength); Ds%9cp*6  
// fileSplitterFetch[nPos.length-1].start(); [[:UhrH-  
?PBa'g  
E,{GU  
//等待子线程结束 L'zE<3O'3  
//int count = 0; a q3~!T;W  
//是否结束while循环 ,Bisu:v6FW  
boolean breakWhile = false; c |>=S)|  
:P3{Nxa  
I Byf_E;r  
while(!bStop) ?Bo?JMV  
{ D`6iDi t  
write_nPos(); ')B =|T)  
Utility.sleep(500); J,f/fPaf7  
breakWhile = true; 6cM<>&e  
rh@r\ H@j  
f|OI`  
for(int i=0;i<nStartPos.length;i++) 8wr8:( Y$  
{ S_J,[#&  
if(!fileSplitterFetch.bDownOver) *HR +a#o  
{ et=7}K]l  
breakWhile = false; geksjVwPH  
break; R{HV]o|qk  
} sf(i E(o  
} O|QUNr9  
if(breakWhile) KU-'+k2s;p  
break; j~bAbOX12  
]*qU+&  
-"=)z /S  
//count++; #ZJMlJ:q`"  
//if(count>4) OTj,O77k  
// siteStop(); Hou*lCA  
} bNGCOj  
Z7fg 25  
T-'~?[v  
System.err.println("文件下载结束!"); 'BY-OA#xJ  
} w/W7N   
catch(Exception e){e.printStackTrace ();} u:@U $:sZ  
} k;k}qq`d  
=!BobC- [b  
[$pmPr2  
//获得文件长度 jNA1O68N  
public long getFileSize() )P?IqSEA%  
{ B:< ]Hl$  
int nFileLength = -1; .h4\{|  
try{ ?s?$d&h  
URL url = new URL(siteInfoBean.getSSiteURL()); 5u r)uz]w8  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zvY+R\,in  
httpConnection.setRequestProperty("User-Agent","NetFox"); 3uV4/% U  
!4WEk  
7\ypW$Ot  
int responseCode=httpConnection.getResponseCode(); KB!5u9  
if(responseCode>=400) ib$nc2BPb  
{ KVkMU?6  
processErrorCode(responseCode); & ze>X  
return -2; //-2 represent access is error =bLY /  
} d--'Rn5  
TJ(K3/)Z  
9XLFHV("  
String sHeader; WA6!+Gy  
KL [ek  
c3)C{9T](  
for(int i=1;;i++) yHeEobvb  
{ 4nqoZk^R  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); w8Vw1wW  
//Utility.log(in.readLine()); bc I']WgB-  
sHeader=httpConnection.getHeaderFieldKey(i); Hp Vjee  
if(sHeader!=null) geM6G$V&  
{  fvEAIs  
if(sHeader.equals("Content-Length")) nwA8ALhE  
{ hePPxKQ-  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); OtTBErQNF  
break; 5GQLd  
} >9H@|[C  
} +9XQ[57  
else :7g=b%;  
break; T6#CK  
} WC,+Cn e  
} ?wb+L  
catch(IOException e){e.printStackTrace ();} X^@ I].  
catch(Exception e){e.printStackTrace ();} 17|np2~  
pI.+"Hz  
=IU*}>#  
Utility.log(nFileLength); \.uc06  
wQ+8\ s=  
LD>\#q8a*  
return nFileLength; *Dmx&F=3,5  
} 1L nyWZ  
dRi5hC$  
B@y(.  
//保存下载信息(文件指针位置) <7_KeOLJ  
private void write_nPos() ::5E8919  
{ !#2=\LUC  
try{ ?GA&f2]a  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ORN6vX(1  
output.writeInt(nStartPos.length); "LhvzM-<8  
for(int i=0;i<nStartPos.length;i++) "O[j!fG8,  
{ N587(wZ  
// output.writeLong(nPos); o>Er_r  
output.writeLong(fileSplitterFetch.nStartPos); (X[CsaXt  
output.writeLong(fileSplitterFetch.nEndPos); N K]B?  
} ? "/ fPV-  
output.close(); Iu@y(wyg  
} R\|lt)h  
catch(IOException e){e.printStackTrace ();} n5-)/R[z  
catch(Exception e){e.printStackTrace ();} laKuOx}  
} !7bw5H  
Lw1EWN6}_&  
zSEs?  
//读取保存的下载信息(文件指针位置) )D&M2CUw"f  
private void read_nPos() cO2& VC  
{ !4"^`ors$  
try{ U69u'G:  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); fBn"kr;  
int nCount = input.readInt(); 4Y> Yi*n  
nStartPos = new long[nCount]; (-77[+2  
nEndPos = new long[nCount]; Ny- [9S-<  
for(int i=0;i<nStartPos.length;i++) YevyN\,}V!  
{ M:KbD|  
nStartPos = input.readLong(); G!N{NCq  
nEndPos = input.readLong(); l_'[27  
} N==ZtKj F  
input.close(); (>4aibA'P  
} :~Q!SL N  
catch(IOException e){e.printStackTrace ();} }R[#?ty;]  
catch(Exception e){e.printStackTrace ();} $?G"GQ!.  
} J5p"7bc  
$rF=_D6  
kum#^^4G|  
private void processErrorCode(int nErrorCode) 7hW+T7u?  
{ ._w8J"E5  
System.err.println("Error Code : " + nErrorCode); :<Y}l-x  
} [D-Q'"'A  
9^"b*&>P  
g"s$}5{8:  
//停止文件下载 ,#FLM`  
public void siteStop() 9E2j!  
{ acP+3u?r  
bStop = true; Rlnbdb;!k  
for(int i=0;i<nStartPos.length;i++) 1OLqL  
fileSplitterFetch.splitterStop(); ?bZovRx  
\!vN   
gWABY%!}  
} v~3B:k:?l  
} 3f " %G\  
//负责部分文件的抓取 v2r&('pV  
**FileSplitterFetch.java UJfT!==U  
*/ >d"3<S ; b  
package NetFox; n\Fp[9+Z\  
&AVpLf:?  
{t"+ 3zy'  
import java.io.*; Oa;X +  
import java.net.*; EN{]Qb06A  
!Cgx.   
YjF|XPv+ l  
public class FileSplitterFetch extends Thread { CQ`=V2:"ON  
LE5.b]tv2  
sDr/k`>  
String sURL; //File URL SG}V[Glk  
long nStartPos; //File Snippet Start Position Gb[`R}^dq  
long nEndPos; //File Snippet End Position ;6@r-r  
int nThreadID; //Thread's ID Spo?i.#  
boolean bDownOver = false; //Downing is over  ~ ~uAc_  
boolean bStop = false; //Stop identical 8l}1c=A}Vi  
FileAccessI fileAccessI = null; //File Access interface 2!&&|Mh}  
j'[m:/  
^ -FX  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException yR{x}DbG  
{ b" xmqWa  
this.sURL = sURL; CT0l!J~5m~  
this.nStartPos = nStart; 7Dnp'*H  
this.nEndPos = nEnd; l`kWz5[~  
nThreadID = id; 5aad$f  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .=m,hu~  
} x!\ONF5$  
oH0X<'  
43?^7_l-  
public void run() _&K  
{ |KB0P@=a  
while(nStartPos < nEndPos && !bStop) j!7`]  
{ U\/5;Txy(  
yC 77c=  
UnVm1ZWZ  
try{ .@ xF6UZ  
URL url = new URL(sURL); +("7ZK?  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0 a]/%y3V  
httpConnection.setRequestProperty("User-Agent","NetFox"); ??TMSH  
String sProperty = "bytes="+nStartPos+"-"; QL6C,#6  
httpConnection.setRequestProperty("RANGE",sProperty); Kp+CH7I*  
Utility.log(sProperty); Rqwzh@}  
,q(&)L$S  
b jAnaya  
InputStream input = httpConnection.getInputStream(); ThPE 0V  
//logResponseHead(httpConnection); 7+x? " 4  
]9}HEu;1M  
tm7u^9]  
byte[] b = new byte[1024]; sr@j$G#uW5  
int nRead; r{L4]|(utY  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) eh,~^x5  
{ l5l>d62  
nStartPos += fileAccessI.write(b,0,nRead); SIBoCs5  
//if(nThreadID == 1) eEhr140  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yj4+5`|f  
} # :T-hRu  
pJN${  
Kwc6mlw~M  
Utility.log("Thread " + nThreadID + " is over!"); VqL.iZ-  
bDownOver = true; +[SgO}sF  
//nPos = fileAccessI.write (b,0,nRead); 2pdvWWh3l  
} pP(XIC  
catch(Exception e){e.printStackTrace ();} cyxuK*x<  
} E}%hz*Q)(  
} 5[j`6l  
T~h5B(J;  
AeAp0cbet  
//打印回应的头信息 ;3_l@dP"  
public void logResponseHead(HttpURLConnection con) .z13 =yv  
{ 52upoU>}2  
for(int i=1;;i++) [ sd;`xk  
{ qj cp65^  
String header=con.getHeaderFieldKey(i); ]%Zz \Q  
if(header!=null) NEa>\K<\  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); p4VeRJk%  
Utility.log(header+" : "+con.getHeaderField(header)); zhY+x<-  
else hzk6rYg1  
break; nQ|r"|g  
} r\nx=  
} ie-vqLc  
zE;bBwy&  
Be+0NXLVy  
public void splitterStop() %e*@CbO$  
{ <0S=,!  
bStop = true; S*AERm   
} Lg"C]  
e.c3nKXZ q  
KR7@[  
} mo~*C   
p}[zt#v  
=_YG#yS  
/* 0ZQ'_g|%  
**FileAccess.java ccd8O{G.M  
*//文件访问(定位,写) 1:Si,d,wh  
package NetFox; 4 Jx"A\5*G  
import java.io.*; YJ(*wByM  
d#2$!z#  
yoAfc  
public class FileAccessI implements Serializable{ &~CY]PN.  
B c2p(z4  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >vo=]c w  
RandomAccessFile oSavedFile; q\\gpCgp  
long nPos; vFEQ7 qI  
/  g 2b  
IHRGw  
public FileAccessI() throws IOException kA7mLrON  
{ H(Eh c  
this("",0); I@\OaUGr+  
} BC'llD  
OT&k.!=  
Y2'cs~~$Ce  
public FileAccessI(String sName,long nPos) throws IOException ]~Y<o  
{ (rg;IXAq%  
oSavedFile = new RandomAccessFile(sName,"rw"); KD^N)&k^Kp  
this.nPos = nPos; ZoArQ(YFy  
oSavedFile.seek(nPos); h;3cd0  
} 3j3N!T9  
Fv<`AU  
r1fGJv1!o  
public synchronized int write(byte[] b,int nStart,int nLen) B7]MGXC  
{ P'Q+GRpSw  
int n = -1; /r_~: 3F  
try{ H.UX,O@  
oSavedFile.write(b,nStart,nLen); [V:\\$  
n = nLen; 2k<;R':  
} fA89|NTSUh  
catch(IOException e) |r bWYl.b  
{ <oz!H[!  
e.printStackTrace (); zRPeNdX  
} vB+ '  
Zdn~`Q{  
"1, pHR-+R  
return n; 0T46sm r  
} 'fPdpnJ<  
r [ K5w  
MX+ Z ?  
} |\n_OS 7  
N<DGw?Rl  
jbR0%X2  
/* E\C9|1)  
**SiteInfoBean.java K(q-?n`<  
*/ *YlV-C<}W"  
package NetFox; >$2V%};  
"le>_Ze_>|  
p0pWzwTG3  
public class SiteInfoBean { ?mlNL/:  
h>Hb `G<  
-1J[n0O.  
private String sSiteURL; //Site's URL + T8B:  
private String sFilePath; //Saved File's Path uw2hMt (N  
private String sFileName; //Saved File's Name D.mHIsX6\  
private int nSplitter; //Count of Splited Downloading File /JT#^Y  
a.z;t8  
`UBYp p  
public SiteInfoBean() gJM`[x`T  
{//nSplitter的缺省值为5 Y/7 $1k  
//default value of nSplitter is 5 H@l}WihW  
this("","","",5); !fj(tPq  
} ZI=v.wa  
<ZB1Vi9}8  
?@V[#.  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) FHV-BuH5  
{ ^+g$iM[`f  
sSiteURL= sURL; jRL<JZ1N  
sFilePath = sPath; )&!&AlLn  
sFileName = sName; :kGU,>BN  
this.nSplitter = nSpiltter; KIWe@e  
%dY<=x#b  
xNbPsoK  
} yiO. z  
F8apH{&t  
50={%R  
public String getSSiteURL() k-}b{  
{ 8Ac:_Zg  
return sSiteURL; sM9+dh  
} ^`G}gWBx}w  
l]5w$dded~  
O?|gp<=d  
public void setSSiteURL(String value) _8E/) M  
{ &%-73nYw  
sSiteURL = value; N ,z6y5Lu  
} G.UI|r /Kz  
IC7M$  
[Vma^B$7Vj  
public String getSFilePath() ,{mCf ^  
{ ?Ec7" hK  
return sFilePath; f`Fi#EKT  
} zE_i*c"`  
Gh}*q|Lz  
ukUGvK  
public void setSFilePath(String value) v\{!THCSh  
{ vuYSVI2=H  
sFilePath = value; O6OP =K!t:  
} Er{>p|n =  
yNTK .  
ej"+:. "\e  
public String getSFileName() 0vw4?>Jf@  
{ VTH> o>g  
return sFileName; >qF CB\(  
} ^- d%r  
-(=eM3o-9m  
J Px~VnE%%  
public void setSFileName(String value) yYfs y?3  
{ hyFyP\u]  
sFileName = value; z5 YWt*nm  
} -jiG7OL  
OtNd,U.dE  
1 9CK+;b  
public int getNSplitter() RVQh2'w  
{ &e!7Z40w@&  
return nSplitter; SBS3?hw  
} bR)(H%I  
.*)2SNH  
a8UwhjFO  
public void setNSplitter(int nCount) 7K98#;a)5  
{ zld#qG6  
nSplitter = nCount; c.e2M/  
} i,/0/?)*_  
} NN?`"Fww  
gp\<p-}  
uu>Pkfo  
/* @8I4[TE  
**Utility.java ;N?]eM}yf  
*/ p|p l  
package NetFox; w}YlVete  
Nb'''W-iu  
]'=)2 .}  
public class Utility { W}mn}gTQ  
>: g3k  
R)m'lMi|  
public Utility() \r+8qC[,  
{ XY3v_5~/1F  
ZNvEW  
"9Q40w\  
} =D<PVGo9  
$[a8$VY^Cm  
//线程睡眠 0a XPPnuX  
public static void sleep(int nSecond) ]Yn_}Bq  
{ SR |`!  
try{ @/ohg0  
Thread.sleep(nSecond); P&^;656r  
} *(T:,PY  
catch(Exception e) /$p6'1P8  
{ R1$:~p2m  
e.printStackTrace ();   t!_<~  
} ElW~48  
} x5-}h*  
S;286[oq@  
//日志 Rx=>6,)'  
public static void log(String sMsg) lUMS;H(  
{ fUA uqfj[  
System.err.println(sMsg); 1`qMj0Y_  
} IvtJ0  
U ^5Kz-5.  
_ =VqrK7T  
public static void log(int sMsg) vkEiOFU!u  
{ sW'2+|3"  
System.err.println(sMsg); +Z !)^j  
} .Z `av n  
} hRD=Y<>A  
M:[ %[+6  
I7n"&{s"*  
/* (<xfCH F5  
**TestMethod.java EWkLXU6t  
*/ r w2arx  
package NetFox; FWG6uKv  
3@$,s~+ 3  
 VoWNW  
public class TestMethod { jk[1{I/  
AW!?"xdZ  
:fZ}o|t7  
public TestMethod() QLiu2U o  
{ ///xx/weblogic60b2_win.exe 8y.wSu  
try{ !C3MFm{B  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |es?;s'  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ($;77fPR  
SiteFileFetch fileFetch = new SiteFileFetch(bean); `-J%pEIza  
fileFetch.start(); i/`m`qdg  
} VyXhl;  
catch(Exception e){e.printStackTrace ();} .yqM7U_  
f=r<nb'H  
-~v2BN/  
} R\G0'?h >  
bU2Z[sn.  
] [+#;avU  
public static void main(String[] args) v,-HU&/*B  
{ xqG[~)~  
new TestMethod(); $!-c-0ub  
} R6kD=JY/!  
} J\:R|KaP<p  
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