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http断点续传简单实现(java)

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/* tHmV4H$  
**SiteFileFetch.java HX#$ ^@Q(  
*/ ]$)U~)T iW  
package NetFox; =gAn;~  
import java.io.*; dmYgv^t  
import java.net.*; Z#zXary5s  
5}4>vEn  
Ey&gZ$|&  
public class SiteFileFetch extends Thread { oAF#bj_f  
3vj 1FbY  
\hD jZ  
SiteInfoBean siteInfoBean = null; //文件信息Bean xM_+vN *(  
long[] nStartPos; //开始位置 Yan,Bt{YJ  
long[] nEndPos; //结束位置 vw*,_f  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 -r%k)4_  
long nFileLength; //文件长度 h3Y|0-D  
boolean bFirst = true; //是否第一次取文件 c JOT{  
boolean bStop = false; //停止标志 ei!Yxw8d  
File tmpFile; //文件下载的临时信息 !h70<Q^  
DataOutputStream output; //输出到文件的输出流 ' 1D1y'  
Q tl!f  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) rLE5fl5W  
public SiteFileFetch(SiteInfoBean bean) throws IOException fjLS_Q ;h  
{ C/ENJ&  
siteInfoBean = bean; s:*" b'  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); +jyWqld.K1  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Lnc>O'<5P9  
if(tmpFile.exists ()) IzlmcP3  
{ &+")~2 +  
bFirst = false; H'?dsc  
read_nPos(); Cznp(z  
} I(va;hG<o  
else }{F1Cr   
{ g]9A?#GyE  
nStartPos = new long[bean.getNSplitter()]; ;uaZp.<um&  
nEndPos = new long[bean.getNSplitter()]; O0QK `F/)*  
} I` q"  
O~c\+~5M*  
QFU1l"(qGk  
"$U!1  
} S?u@3PyJm  
y\mK?eR  
(3N;-   
public void run() LfX[(FP  
{ >#|%y>g .o  
//获得文件长度 z K6'wL!!I  
//分割文件 Y(R .e7]  
//实例FileSplitterFetch !h>aP4ofT  
//启动FileSplitterFetch线程  K2D, *w  
//等待子线程返回 'Omj-o'tn9  
try{ ~#|Pe1Y  
if(bFirst) >?(}F':  
{ <CN+VXF  
nFileLength = getFileSize(); - aQf( =  
if(nFileLength == -1) I2)#."=Ew  
{ THmmf_w@  
System.err.println("File Length is not known!"); Cn.x:I@r  
} -GT&46hX  
else if(nFileLength == -2) sW0<f& 3  
{ A;7At!kK  
System.err.println("File is not access!"); ^ ^k]2oG  
} ,2]a<0m  
else Qn`Fq,uvL  
{ en-HX3'  
for(int i=0;i<nStartPos.length;i++) gJ?Vk<hp  
{ }\]J?I+A  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); F~x>\?iN  
} Iz9b5  
for(int i=0;i<nEndPos.length-1;i++) z<,-:=BC"  
{ Qw.j  
nEndPos = nStartPos[i+1]; f~{4hVA  
} !1xX)XD4y  
nEndPos[nEndPos.length-1] = nFileLength; (}MN16!  
} T*rx5*:o  
} %Mr^~7nN  
{qb2!}FQ  
Kq;s${ |G  
//启动子线程 []hC*  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &'oZ]}^ 0  
for(int i=0;i<nStartPos.length;i++)  f~w!Z  
{ DGO\&^GT^  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fl o9iifZ  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -HUlB|Q8r  
nStartPos,nEndPos,i); zA*I=3E(  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3oMhsQz~z  
fileSplitterFetch.start(); /s "Lsbe  
} S(Q=2Y  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5'S~PQka*  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); d< b,].  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", */y (~O6  
nEndPos = " + nFileLength); 4x2,X`pe3  
// fileSplitterFetch[nPos.length-1].start(); P:fcbfH+  
Q$8K-5U%  
i]}`e>fF  
//等待子线程结束 Hg 2Rcl  
//int count = 0; i2 G.<(3O  
//是否结束while循环 aW(H n[}^  
boolean breakWhile = false; FwqaWEk  
<L+y 6B  
evGUl~</~  
while(!bStop) >6 A8+=  
{ LyG&FOf?  
write_nPos(); PiF&0;  
Utility.sleep(500); agj_l}=gO  
breakWhile = true; UzT"Rb:e  
DgODTxiX  
N~+ e\K6  
for(int i=0;i<nStartPos.length;i++) C(}N*e1  
{ 'yNS(Bg=  
if(!fileSplitterFetch.bDownOver) Zx 5Ue#I  
{ -;j ' =?  
breakWhile = false; y8$I=  
break; ?V' zG&n@  
} cA{7*=G?  
} :4/37R(~l8  
if(breakWhile) oP_}C[  
break; MP$9W)  
?C(3TKH  
uc]`^,`2/  
//count++; `]j:''K  
//if(count>4) bz|-x"qk  
// siteStop(); aM|;3j1p  
} +\U#:gmw  
DLd1Cl:"~:  
n 'E:uXv"  
System.err.println("文件下载结束!"); JXq l=/%  
} >$G'=N:=X&  
catch(Exception e){e.printStackTrace ();} _ls i,kg?  
} f]48>LRE8  
Eh&-b6:  
T':} p2}w+  
//获得文件长度 PIM4c  
public long getFileSize() jP}Ix8vc=  
{ #}S<O_  
int nFileLength = -1; PDkg@#&y,k  
try{ >*Ctp +X@  
URL url = new URL(siteInfoBean.getSSiteURL()); {8T/;K@  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L&hv:+3N  
httpConnection.setRequestProperty("User-Agent","NetFox"); _m*FHi  
A8T8+M:  
U5yBU9\G  
int responseCode=httpConnection.getResponseCode(); T,/:5L9  
if(responseCode>=400) T7?cnK"  
{ S,vh  
processErrorCode(responseCode); a~&euT2  
return -2; //-2 represent access is error ZK5 wZU  
} 5F$~ZDu  
<5o oML]nP  
F}c}I8Ao  
String sHeader; /&+*X)#v  
k nljc^  
og`K! d~  
for(int i=1;;i++) C9^C4   
{ _*fOn@Vwo  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ^T*'B-`C7X  
//Utility.log(in.readLine()); 9wdl1QS  
sHeader=httpConnection.getHeaderFieldKey(i); A.cNOous|  
if(sHeader!=null) Td 5yRN! ?  
{ $[V-M\q  
if(sHeader.equals("Content-Length")) PnZY%+[I  
{ *9tRh Rc  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _&e$?hY  
break; (O"-6`w[  
} ^NXxMC( e+  
}  6h?)x  
else +;bP.[Z  
break; \S0QZQbz/  
} {<Y\flj{@m  
} ).IK[5Q`  
catch(IOException e){e.printStackTrace ();} odKdpa Zc[  
catch(Exception e){e.printStackTrace ();} $7*@TMX  
R?HuDxHk  
eXi}-~o  
Utility.log(nFileLength); -lS(W^r4  
w5;d/r<q  
SAhk`_  
return nFileLength; *K;s*-|U  
} Igh=Z %  
@1s 2# )l(  
3|PV.  
//保存下载信息(文件指针位置) s'/ZtH6>C  
private void write_nPos() cYz|Ux  
{ cs?IzIQ  
try{ ET;-'vd  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ''H;/&nDX  
output.writeInt(nStartPos.length); ',]^Qu`a  
for(int i=0;i<nStartPos.length;i++) p4vX3?&1W  
{ /" @cv{  
// output.writeLong(nPos); =F09@C,  
output.writeLong(fileSplitterFetch.nStartPos); }#2I/dn  
output.writeLong(fileSplitterFetch.nEndPos); J+m1d\lBu  
} b}!T!IP}  
output.close(); YI?tmqzt  
} \.YJs"<3  
catch(IOException e){e.printStackTrace ();} "'~&D/7  
catch(Exception e){e.printStackTrace ();} 5DL(#9F8b9  
} ),XDY_9K  
rmeGk&*R8  
ht2J, 1t  
//读取保存的下载信息(文件指针位置) }aL&3[>>  
private void read_nPos() (BGflb  
{ upiYo(sN.  
try{ 3;F up4!4}  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); C(n_*8{  
int nCount = input.readInt(); cUr5x8<W).  
nStartPos = new long[nCount]; _ ($U\FW  
nEndPos = new long[nCount]; <xUX&J=;  
for(int i=0;i<nStartPos.length;i++) NIG* }[}P  
{ L[tq@[(IJ  
nStartPos = input.readLong(); 2%vG7o,#  
nEndPos = input.readLong(); APyH.]mQ  
} vngn^2  
input.close(); Y%^qt]u.8  
} qVE <voB8  
catch(IOException e){e.printStackTrace ();} R|[gEavFl  
catch(Exception e){e.printStackTrace ();} cH6J:0>W  
} d "25e"(~F  
S5[}kfe  
:"gu=u!  
private void processErrorCode(int nErrorCode) K_%gda|l+  
{ :kvQ3E0  
System.err.println("Error Code : " + nErrorCode); (w`j?c1  
} pYh\l.@qf  
yM*_"z!L  
Rbcu5.6  
//停止文件下载 Jk57| )/  
public void siteStop() T@d4NF#  
{ bzh:  
bStop = true; )!Zm*(  
for(int i=0;i<nStartPos.length;i++) lsU`~3nr  
fileSplitterFetch.splitterStop(); { a_&L  
2E0oLl[  
D~)bAPAD  
} 3x)jab  
} D!mx&O9  
//负责部分文件的抓取 yT[)V[}  
**FileSplitterFetch.java ,6aF~p;wI|  
*/ [y"Yi PK  
package NetFox; 0E#?H0<OeG  
cUTG! P\R  
T:g%b @  
import java.io.*; lT_dzO  
import java.net.*; n( zzH  
]{18-=  
8|tnhA]~  
public class FileSplitterFetch extends Thread { Esf\Bo"  
T=':$(t  
(#nB90E{*  
String sURL; //File URL `!<#'PR  
long nStartPos; //File Snippet Start Position nZ[`Yrq)0  
long nEndPos; //File Snippet End Position VYkUUp  
int nThreadID; //Thread's ID @_ Tq>tOr&  
boolean bDownOver = false; //Downing is over =l>=]O~h  
boolean bStop = false; //Stop identical ohi0_mBz  
FileAccessI fileAccessI = null; //File Access interface #!t6'*  
{/i&o  
Y?:" nhN  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException <MJ-w1A  
{ mpD[k9`x#  
this.sURL = sURL; .@psW0T%  
this.nStartPos = nStart; lS?#(}a1)  
this.nEndPos = nEnd; `:W}yo<F  
nThreadID = id; 8Fv4\dr  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0a:@DOzT  
} Wm/0Pi  
j+Q+.39s-~  
XQZiJ %'  
public void run() &3:<WU:U  
{ =oTj3+7  
while(nStartPos < nEndPos && !bStop) ]3uj~la  
{ C)ic;!$Qhb  
!*o{xq   
{ }P~nP  
try{ Jt3*(+J>/  
URL url = new URL(sURL); 8d(l)[GZt  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &.JJhX  
httpConnection.setRequestProperty("User-Agent","NetFox"); vJ e c+a  
String sProperty = "bytes="+nStartPos+"-"; XV1XzG#C  
httpConnection.setRequestProperty("RANGE",sProperty); `Dp4Z>| K  
Utility.log(sProperty); f& Vx`oj  
&U\//   
" Rn@yZV  
InputStream input = httpConnection.getInputStream(); UQjYWXvi  
//logResponseHead(httpConnection); pW_mS|  
*A0*.>@N  
`E |>K\  
byte[] b = new byte[1024]; b{;LbHq+G  
int nRead; $Km~x  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) zEDN^K '  
{ w@H@[x  
nStartPos += fileAccessI.write(b,0,nRead); K;]Dh?  
//if(nThreadID == 1) 9&{HD  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); PNH>LT^  
} 9r ](/"=f  
'rrnTd c  
# ELYPp]6  
Utility.log("Thread " + nThreadID + " is over!"); %- Ga  ^[  
bDownOver = true; ps33&  
//nPos = fileAccessI.write (b,0,nRead); Aa^w{D  
} 0@&/W-VXg  
catch(Exception e){e.printStackTrace ();} zIr4!|X  
} G6s3 \de#U  
} |Rz}bsrZ  
#I#_gjJkx  
+1c[!;'  
//打印回应的头信息 %DKC/%  
public void logResponseHead(HttpURLConnection con) 8F/zrPG  
{ |][PbN D  
for(int i=1;;i++) 3U*4E?g  
{ 0O(Vyy  
String header=con.getHeaderFieldKey(i); 2Hk21y\  
if(header!=null) $F6GCM3Cx  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); G`f|#-}  
Utility.log(header+" : "+con.getHeaderField(header)); gi+FL_8CzU  
else !ZY1AhGZ  
break; \W|ymV_Ki  
} Eo@rrM:  
} t-Ble  
t-SZBNb  
AvB21~t&]  
public void splitterStop() .e\PCf9v  
{ lDVgW}o@  
bStop = true; ^G "Qp8 "  
} 4@0Z<8Mo  
cL4Xh|NBp  
F <{k~   
} 6iY(RYZ7-  
5kCXy$"%  
nLR   
/* % @!hf!  
**FileAccess.java ES)_X:\X?V  
*//文件访问(定位,写) eWXR #g!%>  
package NetFox; Wr+1e1[  
import java.io.*; RtEx WTc  
Q1!+wC   
f]2;s#cu  
public class FileAccessI implements Serializable{ xu@xP5GB^  
WA5.qw  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #-l+c u{  
RandomAccessFile oSavedFile; =[0| qGzg  
long nPos; q-S#[I+g  
tO3#kV\,  
IV%Rph>d  
public FileAccessI() throws IOException z}Vg4\x&  
{ 0|,Ij $  
this("",0); CDT;AdRw7  
} r+tHVh  
3!8u  
$5DlCN  
public FileAccessI(String sName,long nPos) throws IOException M2nUY`%#v  
{ ITD&w g  
oSavedFile = new RandomAccessFile(sName,"rw"); L#fK ,r8  
this.nPos = nPos; mNJCV8 <  
oSavedFile.seek(nPos); 6UU<:KH  
} 0JW =RW  
u.}H)wt  
<(1[n pS&+  
public synchronized int write(byte[] b,int nStart,int nLen) (Mw+SM3<  
{ w,t !<i  
int n = -1; g O/\Yi  
try{ QE721y   
oSavedFile.write(b,nStart,nLen); biRkq c;  
n = nLen; ADA}_|O  
} W9S6 SO^\  
catch(IOException e) .u]d5z BR  
{ v=DC3oh-  
e.printStackTrace (); u R]8ZT")  
} Dn`  
z~ua#(z1S  
V14+?L  
return n; znAo]F9=J"  
} 9}+X#ma.Nc  
27MwZz  
bnH:|-?q  
} |<%v`*  
DeI3(o7  
B/Ltb^a  
/* s0DT1s&  
**SiteInfoBean.java 'f8'|o)  
*/ ;_0frX  
package NetFox; $y%IM`/w  
GE=PaYz  
>[Tt'.S!?  
public class SiteInfoBean { RL*b4 7,  
wM}AWmH  
Kd*=-  
private String sSiteURL; //Site's URL nuw7pEW@?  
private String sFilePath; //Saved File's Path t >Rh  
private String sFileName; //Saved File's Name n*9nzx#q  
private int nSplitter; //Count of Splited Downloading File 2I 7|hZ,  
o3:BH@@  
D5Z)"~'  
public SiteInfoBean() -op)X>  
{//nSplitter的缺省值为5 fnIF<Zt  
//default value of nSplitter is 5 )[ejb?{d  
this("","","",5); 8[#EC3  
} U[z2{\  
f<y3/jl4  
a3,A_M}M'  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Hk$do`H-=Y  
{ UK)wV  
sSiteURL= sURL; 4~2 9,  
sFilePath = sPath; t_+owiF)M  
sFileName = sName; B_RF)meux  
this.nSplitter = nSpiltter; &ViK9  
-?-yeJP2  
\y+^r|IL  
} ZuKOscVS#T  
"`h.8=-  
COj^pdE3  
public String getSSiteURL() ;WgzR_'!'  
{ ,[3}t%Da  
return sSiteURL; fP 3t0cp  
} PJ,G_+b!  
(-VH=,Md  
f`8?]@y{  
public void setSSiteURL(String value) B;nIKZ  
{ *\*]:BIe&v  
sSiteURL = value; gUYTVp Vf  
} a%`L+b5-$  
)~IOsTjI  
\Qq YH^M  
public String getSFilePath() X]dN1/_  
{ EAE#AB-A  
return sFilePath; yoz-BS  
} )( pgJLW  
L]l?_#*x  
s.a@uR^  
public void setSFilePath(String value) s+^1\  
{ 4\j1+&W   
sFilePath = value; 1B$8<NCQ=?  
} 'C@yJf  
%BQ?DTtb7'  
W,:j >v g  
public String getSFileName() 09i7 7  
{ Vddod  
return sFileName; 8C*xrg#g:  
} sXYXBX[  
5C9 .h:c4y  
rS+ >oP}  
public void setSFileName(String value) z?GtC{L9  
{ 'a$/ !~X  
sFileName = value; |)mUO:*  
} M0hR]4T  
g!i45]6[Nw  
#%{  
public int getNSplitter() %}unlSTPP  
{ }H/94]~tH  
return nSplitter; ~+PKWs'}F  
} lB7/oa1]>  
iz+,,UH  
}4Q3S1|U  
public void setNSplitter(int nCount) v!=e]w6{  
{ Z1p%6f`  
nSplitter = nCount; w9Nk8OsL  
} &SPIu,  
} Ga` 8oY+~  
bPMf='F{r  
SQN{/")T  
/* <~e*YrJ?-  
**Utility.java SCjVzvG$yg  
*/ 2o 7o~r  
package NetFox; BF"eVKA  
%Rf{v5  
u3DFgl3-7  
public class Utility { sosIu  
kmt+E'^]  
4$4Tx9C  
public Utility() S+?*l4QK  
{ .5tXwxad"  
W k"_lJ  
|aj]]l[@S  
} H~:g =Zw  
}ee3'LUPX  
//线程睡眠 j`_Z`eG  
public static void sleep(int nSecond) e.(RhajB  
{ ~8'HX*B]z  
try{ |1Nz8Vr.  
Thread.sleep(nSecond); mn(MgJKQ\  
} ANR611-a  
catch(Exception e) )P|/<>z  
{ V1A7hRjxvG  
e.printStackTrace (); yKmHTjX=  
} #XNURj  
} "*KOU2}C  
kn WI7  
//日志 i6i;{\tc  
public static void log(String sMsg) F |_mCwA  
{ ,pW^>J  
System.err.println(sMsg); VotI5O $  
} N8!e(Y K_  
r)<n)eXeD  
.SBN^fq  
public static void log(int sMsg) dhuIVBp!!e  
{ T<RWz  
System.err.println(sMsg); Iapzhy2l  
} >_X(rar0  
} wHQYBYKcd  
z] |Y   
qLB(Th\&'  
/* /#}%c'  
**TestMethod.java 7/\SN04l  
*/ / $'M  
package NetFox; M F$NcU  
P[e#j  
l%`~aVGJ  
public class TestMethod { -Q1~lN m:  
b+BX >$  
0%3T'N%  
public TestMethod() C+gu'hD  
{ ///xx/weblogic60b2_win.exe 1i Q(q\%  
try{ 5zt5]zl'  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); l_2YPon  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Q}#H|@  
SiteFileFetch fileFetch = new SiteFileFetch(bean); +:z%#D  
fileFetch.start(); y|WOw(#  
} CS"p3$7,  
catch(Exception e){e.printStackTrace ();} P?y{ 9H*  
S_Vquw(+  
eh3CVgH91;  
} -AKbXkc~\  
o7g6*hJz  
?\a';@h  
public static void main(String[] args) ,Ne v7X[0  
{ {1GIiP-U  
new TestMethod(); "~IGE3{  
} nm<S#i*  
} u?8e>a  
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