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http断点续传简单实现(java)

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/* %/BBl$~ji  
**SiteFileFetch.java e7tio!  
*/ o6:@j#b  
package NetFox; wr~Qy4 ny  
import java.io.*; [Fv_~F491  
import java.net.*; deJ/3\t  
I:0dz:T7*  
[ua[A;K  
public class SiteFileFetch extends Thread { V{ ~~8b1E  
c7R&/JV  
z2Z}mktP  
SiteInfoBean siteInfoBean = null; //文件信息Bean .EvP%A m  
long[] nStartPos; //开始位置 B1]FB|0's  
long[] nEndPos; //结束位置 c[$i )\0  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 )|#ExyRO  
long nFileLength; //文件长度 $.31<@T7  
boolean bFirst = true; //是否第一次取文件 'v=BAY=Ef  
boolean bStop = false; //停止标志 ap,zC)[  
File tmpFile; //文件下载的临时信息 MZqHL4<|  
DataOutputStream output; //输出到文件的输出流 ,XI=e=  
c` N_MP  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) )@] W=  
public SiteFileFetch(SiteInfoBean bean) throws IOException .-[]po  
{ "!uS!BI?  
siteInfoBean = bean; T5}5uk9  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); g|h;*  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Z_7TD)  
if(tmpFile.exists ()) $"k1^&&E  
{ %NfH`%`  
bFirst = false; 02)Ybp6y  
read_nPos(); +UX} "m~W  
} 2sVDv@2  
else ?}S!8;d  
{ 6WoFf  
nStartPos = new long[bean.getNSplitter()]; wUfPnAD.'  
nEndPos = new long[bean.getNSplitter()]; E^m)&.+'M  
} /<dl"PWkJv  
C;#gy-  
%eGD1.R  
M'oQ<,yW-  
} Xn5LrLM&  
c{39,oF  
j 20m Z  
public void run() ) q/brCq  
{ xK4E+^ b  
//获得文件长度 dj}P|v/;z  
//分割文件 )Y"t$Iw"  
//实例FileSplitterFetch `6LV XDR  
//启动FileSplitterFetch线程 G^SDB!/@J  
//等待子线程返回 NE3/>5  
try{ )bpdj,  
if(bFirst) AgB$ w4  
{ <y"lL>JR  
nFileLength = getFileSize(); - s2Yhf  
if(nFileLength == -1) #qJ6iA6{  
{ 6Q&i=!fQ  
System.err.println("File Length is not known!"); &4)PW\ioY  
} 0UGAc]!/RZ  
else if(nFileLength == -2) dEor+5}  
{ zm4e+v-  
System.err.println("File is not access!"); m`b:#z  
} ie7TO{W  
else Ct:c%D(L  
{ Tz7R:S.  
for(int i=0;i<nStartPos.length;i++) 1{ ehnH  
{ g91xUG  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ZS@R?  
} I;9DG8C&v*  
for(int i=0;i<nEndPos.length-1;i++) JD AX^]  
{ `_"?$ v2F  
nEndPos = nStartPos[i+1]; C\|HN=2eh  
} 2d<`dQY{l3  
nEndPos[nEndPos.length-1] = nFileLength; Xob(4  
} . ywVGBvJ  
} 1KJ[&jS ]  
G {a;s-OA3  
5 RYrAzQo  
//启动子线程 1-R4A7+3  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Bma.Uln  
for(int i=0;i<nStartPos.length;i++) qSaCl6[Do  
{ E.^u:0:P  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k\ZU%"^J  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), pvRa  
nStartPos,nEndPos,i); s&DAO r!i  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dQ#oY|a  
fileSplitterFetch.start(); H{_6e6`e.  
} lg 1r]  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u:,B&}j  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); : %U lNk  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", w2K>k/v{-  
nEndPos = " + nFileLength); 6*I=% H|  
// fileSplitterFetch[nPos.length-1].start(); t3!~=U  
~$7YEs)  
59?$9}ob  
//等待子线程结束 HLh]*tQG  
//int count = 0; lvUWs  
//是否结束while循环 4hn' b[  
boolean breakWhile = false; RVpo,;:  
a!PN`N28  
} OkK@8?0O  
while(!bStop) )1O|+m k  
{ 8{Vt8>4  
write_nPos(); 9v7}[`^  
Utility.sleep(500); =CaSd|   
breakWhile = true; B;Co`o2  
7}tXF  
/8P7L'Rb  
for(int i=0;i<nStartPos.length;i++) msw=x0{n5  
{ X"T)X#:)  
if(!fileSplitterFetch.bDownOver) @j%7tfW  
{ +.X3&|@k  
breakWhile = false; |Lc.XxBkc  
break; F_V/&OV  
} }w)wW1&  
} 6O'Y@9#  
if(breakWhile) h6D1uM"o   
break; *C^TCyBK;  
<h`}I3Ao  
=z}M(<G  
//count++; T`Xz*\}Zb  
//if(count>4) >~T2MlRux  
// siteStop(); [kI[qByf  
} ,4(m.P10  
WX $AOnEv  
:/;;|lGw  
System.err.println("文件下载结束!"); MhN 8'y(  
} )U{IQE;T#  
catch(Exception e){e.printStackTrace ();} \Zn~y--Z  
} Ystd[  
`V?NS,@$  
")W5`9  
//获得文件长度 y"ms;w'z  
public long getFileSize() Oq 95zo  
{ r<"k /  
int nFileLength = -1; p Acu{5#7  
try{ $u,`bX  
URL url = new URL(siteInfoBean.getSSiteURL()); *,wW-8  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); UR[UZ4G  
httpConnection.setRequestProperty("User-Agent","NetFox"); =AeOkie  
No]#RvEd3  
oCB#i~|>a  
int responseCode=httpConnection.getResponseCode(); w5a;ts_x  
if(responseCode>=400) u"kB`||(  
{ s18A  
processErrorCode(responseCode); Ia>~ph#]{`  
return -2; //-2 represent access is error [Y6ZcO/-i  
} gy/bA  
IZZ $p{  
,*;g+[Bhpl  
String sHeader; ~&+8m=   
4TaHS!9  
A)nE+ec1  
for(int i=1;;i++) {CGk9g" `  
{ ymA8`k5>@  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); `(@{t:L  
//Utility.log(in.readLine()); w#;y  
sHeader=httpConnection.getHeaderFieldKey(i); SdJkno  
if(sHeader!=null) z-`4DlJUS  
{ 8|rlP  
if(sHeader.equals("Content-Length")) 7*47mJyc  
{ }kk[lvhJ  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader));  Kuh)3/7  
break; p[D,.0SuC  
} l/bZE.GJ  
} aOW$H:b  
else 5+*CBG}  
break; 2Vg+Aly4D  
} FX/f0C3CK  
} #vT~D>zj  
catch(IOException e){e.printStackTrace ();} g|)yM^Vqr6  
catch(Exception e){e.printStackTrace ();} ?;p45y~n%  
V"|j Dnn5  
v$R7"  
Utility.log(nFileLength); mB*;>   
wmit>69S  
m?`$NJST  
return nFileLength; YHo*IX')C?  
} =|q@ Q`DB  
C0'_bTfB  
D;X/7 p|>  
//保存下载信息(文件指针位置) \xOv9(  
private void write_nPos() aX35^K /  
{ Mog!pmc{  
try{ ImI, q:[67  
output = new DataOutputStream(new FileOutputStream(tmpFile)); i7xBi:Si  
output.writeInt(nStartPos.length); Bet?]4\_  
for(int i=0;i<nStartPos.length;i++) /U"3LX  
{ 5f#]dgBe  
// output.writeLong(nPos); DbK-3F_  
output.writeLong(fileSplitterFetch.nStartPos); S{qsq\X  
output.writeLong(fileSplitterFetch.nEndPos); r1|;V~ a$~  
} bcFZ ~B  
output.close(); s!/Q>A  
} s C?-L  
catch(IOException e){e.printStackTrace ();} \v([,tiW%  
catch(Exception e){e.printStackTrace ();} /@K1"/fqH  
} o,=dm@j  
&y:SK)  
6>/g`%`N  
//读取保存的下载信息(文件指针位置) e}W|wJ):j@  
private void read_nPos() ,+E"s3NW  
{ Z~ DR,:  
try{ }&IOBYHVDo  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]llvG \  
int nCount = input.readInt(); jftf]n&Z(q  
nStartPos = new long[nCount]; u/X1v-2  
nEndPos = new long[nCount]; 0 I[3%Q{  
for(int i=0;i<nStartPos.length;i++) .T^e8  
{ T3^(I~03  
nStartPos = input.readLong(); CYN|  
nEndPos = input.readLong(); ~ ^) 4*@i6  
} l\~F0Z/O  
input.close(); EB[B0e 7}  
} lag%} ^  
catch(IOException e){e.printStackTrace ();} ^es/xt  
catch(Exception e){e.printStackTrace ();} TllIs&MCe  
} VAZ6;3@cd  
k>72W/L^  
hdx"/.s  
private void processErrorCode(int nErrorCode) kV+O|9  
{ PkxhR;4  
System.err.println("Error Code : " + nErrorCode); r WPoR/M  
} 2<Q3-|/i  
0]`%i G|  
Y` tB5P  
//停止文件下载 x8E!Ko](  
public void siteStop() BFMINq>  
{ _9b;8%? Yf  
bStop = true; OqA#4h4^  
for(int i=0;i<nStartPos.length;i++) OG}m+K&<  
fileSplitterFetch.splitterStop(); p*" H&xA@  
tD\%SiTg=b  
%P-z3 0FHp  
} |fg{Fpc  
} uY Y{M`  
//负责部分文件的抓取 Kv-4VWh  
**FileSplitterFetch.java eh} {\P  
*/ SpiI9)gp  
package NetFox; 3+2cD  
e2$k %c~  
o-%DL*^5  
import java.io.*; FTC,{$  
import java.net.*; G,JNUok  
x9VR>ux&  
AF-uTf  
public class FileSplitterFetch extends Thread { fs wQ*  
 w#\*{EN  
![4<6/2gy  
String sURL; //File URL ) v^;"q"  
long nStartPos; //File Snippet Start Position 8.4+4Vxh   
long nEndPos; //File Snippet End Position \*k}RKDwT  
int nThreadID; //Thread's ID eNw9"X}g  
boolean bDownOver = false; //Downing is over @XFy^?  
boolean bStop = false; //Stop identical b6A]/290x  
FileAccessI fileAccessI = null; //File Access interface *&lNzz5&  
%vFoTu)2  
.3yxg}E>{  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException kA%"-$3  
{ CP!>V:w%9!  
this.sURL = sURL; $d _%7xx  
this.nStartPos = nStart; E8s&.:;+  
this.nEndPos = nEnd; U<H< !NV  
nThreadID = id; yCT:U&8%F  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6`Af2Y_  
} eW^_YG%(  
4` zfrT^  
O+Qt8,  
public void run() *%wfR7G[B  
{ j=~c( B  
while(nStartPos < nEndPos && !bStop) l2LUcI$ x  
{ aL%amL6CX  
?A7_&=J%  
dwAFJhgh  
try{ KM ;'MlO  
URL url = new URL(sURL); P(#by{s  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7Ta",S@m  
httpConnection.setRequestProperty("User-Agent","NetFox"); 8rx"D`{|  
String sProperty = "bytes="+nStartPos+"-"; 3>t^Xu~  
httpConnection.setRequestProperty("RANGE",sProperty); ME%W,B.|"s  
Utility.log(sProperty); ;.4A,7w#  
(( D*kd"  
o:irwfArv  
InputStream input = httpConnection.getInputStream(); ,3tcti~sZ  
//logResponseHead(httpConnection); A$]&j5nh|  
V)8d1S  
,Bg)p_B  
byte[] b = new byte[1024]; qFD#D_O6  
int nRead; r|>a;n Y  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1^4z/<ZWm  
{ ``p( )^zT  
nStartPos += fileAccessI.write(b,0,nRead); -$js5 Gx1  
//if(nThreadID == 1) 0+P<1ui  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >u:t2DxE  
} %8a886;2  
#}Qzu~  
 mOkf   
Utility.log("Thread " + nThreadID + " is over!"); 6*n<emP  
bDownOver = true; P:gN"f6  
//nPos = fileAccessI.write (b,0,nRead); ;P#c!  
} xbv  
catch(Exception e){e.printStackTrace ();} l].Gz`L  
} toCxY+"nbU  
} sw'?&:<"Ow  
0[qU k(=}[  
u d V. $N  
//打印回应的头信息 "A6T'nOP  
public void logResponseHead(HttpURLConnection con) ] _WB^  
{ _z$lg]q  
for(int i=1;;i++) cnR.J  
{ B8'e,9   
String header=con.getHeaderFieldKey(i); "5,tEP!  
if(header!=null) ,c;u]  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <[e E5X(  
Utility.log(header+" : "+con.getHeaderField(header)); oS/cS)N20  
else N=QeeAI}}m  
break; l12_&o"C~  
} y(!Y N7_A  
} P~5[.6gW  
)Uv lEG']  
!5;A.f  
public void splitterStop() jeM/8~^4-  
{ [8o!X)  
bStop = true; t)*MLg<C  
} R\B-cU[,  
nf7l}^/UE  
eXqS9`zKr  
} JQhw>H9&  
:q xd])-  
Xo{|m[,  
/* Gs% cod  
**FileAccess.java q@}eYQ=P|e  
*//文件访问(定位,写) >+ZG {'!j  
package NetFox; JToc("V  
import java.io.*; &GC`4!H  
dvAvG.;U  
AI|8E8h+D  
public class FileAccessI implements Serializable{ o6PDCaT7  
Tjfg[Z/x  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 LyRU2A  
RandomAccessFile oSavedFile; $cxulcay=  
long nPos; ecoi4f  
i+2fWi6Z+  
-xc*R%k  
public FileAccessI() throws IOException sMq*X^z )?  
{ ;!JI$_ -\  
this("",0); S-^RZ"  
} Ez*9*]O*+  
wIv_Z^% V  
CO` %eL ~  
public FileAccessI(String sName,long nPos) throws IOException V?a+u7*U&  
{ b0A*zQA_)  
oSavedFile = new RandomAccessFile(sName,"rw"); UKBVCAK  
this.nPos = nPos; }w0>mA0=H  
oSavedFile.seek(nPos); xMAfa>]{n  
} Iq@:n_~  
_\9|acFT2O  
q\P"AlpC!  
public synchronized int write(byte[] b,int nStart,int nLen) LG0z|x(  
{ /$ -^k[%  
int n = -1; H WOl79-  
try{ $\0%"S  
oSavedFile.write(b,nStart,nLen); PfaBzi9?f  
n = nLen; J;K-Pv +  
} Fo=hL  
catch(IOException e) "pDwN$c  
{ FZW)C'j  
e.printStackTrace (); FJ|6R(T_  
} cK;,=\  
pohA??t2:  
SD"'  
return n; 7>Af"1$g  
} x*G-?Xza)  
CLb~6LD  
+izB(E8&{J  
} x-Kq=LFy.  
Rn (vG-xQ  
*?zyF@K{%  
/* 9 a ED6  
**SiteInfoBean.java :|s!_G<  
*/ G8w<^z>pTg  
package NetFox; O>Vb7`z0<  
U;Iqz1S  
^^u{W|'CaH  
public class SiteInfoBean { hPs7mnSW  
eY)JuJ?  
g:l5,j.K  
private String sSiteURL; //Site's URL woctnT%"Q/  
private String sFilePath; //Saved File's Path nN=o/zd  
private String sFileName; //Saved File's Name K0|8h!WF+  
private int nSplitter; //Count of Splited Downloading File Ue>;h9^  
~nQv yM!$  
t:DZow  
public SiteInfoBean() +:hZ,G?>  
{//nSplitter的缺省值为5 E4a`cGb  
//default value of nSplitter is 5 3yWu-U \k  
this("","","",5);  As&=Pb9  
}  k3[%pS  
+1Qa7 \  
5J d7<AO_  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [jPUAr}  
{ `D0>L '  
sSiteURL= sURL; j-e gsKR  
sFilePath = sPath; wA+QUN3#n  
sFileName = sName; 39xAh*}G]  
this.nSplitter = nSpiltter; )ZU)$dJ>V  
K3uNR w  
#kO.'oIl  
} z=}@aX[  
BT|5"b}  
I7b_dJD;*  
public String getSSiteURL() 9] i$`y  
{ K.y2 $b/  
return sSiteURL; C+, JLK  
} =J2\"6BnzA  
T6gugDQ~.  
}:5_vH0  
public void setSSiteURL(String value) Pc+8CuN?  
{ mVJW"*}8  
sSiteURL = value; DAZzc :1Aj  
} g_kR5Wxpt  
%\5 wHT+)  
3#{{+5G  
public String getSFilePath() 83 O+`f  
{ gnW]5#c@  
return sFilePath; c-|~ABtEpX  
} 8VbHZ9Q  
fOE8{O^W  
X2X.&^  
public void setSFilePath(String value) 5H (CP  
{ zh5$$*\  
sFilePath = value; J^}w,r *=  
} o5!"dxR  
K4]42#  
Rgb1B3gu  
public String getSFileName() {`2R<O  
{ >EVlMt27'  
return sFileName; H3$~S '  
} (AHZmi V  
(8M^|z}q  
e,Ih7-=Er,  
public void setSFileName(String value) + 9vd(c  
{ c6IFt4)g  
sFileName = value; h5+qP"n!?q  
} K"p$ga{  
>Oary  
@x9DV{j)V  
public int getNSplitter() >d.o1<  
{ ``%uq)G=D  
return nSplitter; W<J".2D  
} aBo8?VV]8  
]_cBd)3P}  
YeN /J.R  
public void setNSplitter(int nCount) Y)?dq(  
{ "`b"PQ<x  
nSplitter = nCount; n5nV4 61U  
} @,Je*5$o"  
} #41fRmzC  
kOv2E]  
[;bZQ6JR  
/* TTg>g~t`  
**Utility.java @]*b$6tt  
*/ v&BKl  
package NetFox; gv&%2e}_  
nZ;h&N -_-  
pEUbP,3M:  
public class Utility { O]ZP- WG  
'qGKS:8  
czMu<@c [  
public Utility() bFivHms  
{ 8.Q;o+NU  
NGl/F{<  
TW 2OT }  
} MA\^<x_?L}  
71AR)6<R  
//线程睡眠 ;DMv?-H  
public static void sleep(int nSecond) yN* H IN  
{ }E=:k&IDPB  
try{ D`nW9i7  
Thread.sleep(nSecond); Yg 8AMi  
} 2ckAJcpEb/  
catch(Exception e) d/Q}I[J.u  
{ kF:4 [d  
e.printStackTrace (); 19 h7 M  
} A>;Q<8rh  
} VE4Z;Dr"  
,|gX?[o  
//日志 K".\QF,:  
public static void log(String sMsg) GF6c6TXF@  
{ 2?3D` `  
System.err.println(sMsg); ;^5d^-T  
} .&:GO D  
GA19=gow  
bM]\mo>z<  
public static void log(int sMsg) @(XX68  
{  &Gp~)%  
System.err.println(sMsg); x+j5vzhG)  
} t`b>iX%(1t  
} ->DfT*)  
cY+vnQm  
y %dUry%>  
/* Fs^d-I  
**TestMethod.java kV@*5yc?R  
*/ cswX?MN  
package NetFox; ?Ji.bnfK  
I(6k.PQ  
!FhK<#  
public class TestMethod { Cm:&n|  
lO482l_t  
,vBi)H  
public TestMethod() (2H e]M\  
{ ///xx/weblogic60b2_win.exe fH_G;#q  
try{ xPa>-N=*  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {^TVZdw  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Pb0+ z=L  
SiteFileFetch fileFetch = new SiteFileFetch(bean); *ey<R  
fileFetch.start(); >n,RBl  
} 5#~ARk*?a  
catch(Exception e){e.printStackTrace ();} SB#YV   
wAHW@q9CK  
.r9-^01mG  
} :tP:X+?O  
%N\pfZ2\  
,BM6s,\  
public static void main(String[] args) 9*!C|gC9Ia  
{ <v<TsEI  
new TestMethod(); nQ\ +Za==  
} q7}$F]UM"  
} "hRw_<  
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