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http断点续传简单实现(java)

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/* 4h 5_M8I  
**SiteFileFetch.java ty1fcdFZM  
*/ lXrD!1F  
package NetFox; T!q_/[i~7  
import java.io.*; o|S)C<w  
import java.net.*; <MD;@_Nz\  
\Z5 +$Ij  
)&NAs  
public class SiteFileFetch extends Thread { t\U$8l_;  
2iXoj&3e  
v<rF'D2  
SiteInfoBean siteInfoBean = null; //文件信息Bean L0Vgo<A  
long[] nStartPos; //开始位置 W|Ldu;#  
long[] nEndPos; //结束位置 Iur9I>8h  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 dK?); *w]  
long nFileLength; //文件长度 gqiXmMm:9  
boolean bFirst = true; //是否第一次取文件 _pDjg%A>n  
boolean bStop = false; //停止标志 =(U/CI  
File tmpFile; //文件下载的临时信息 K\=8eg93Z  
DataOutputStream output; //输出到文件的输出流 -R+zeu(e'  
;'kI/(;;C  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) T@+ClZi  
public SiteFileFetch(SiteInfoBean bean) throws IOException OS7R Qw1  
{ 1 0N,?a  
siteInfoBean = bean; B< ;==|  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); &a~=b,  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Jgx8-\ 8  
if(tmpFile.exists ()) w[fDk1H)  
{ :uCdq`SaQl  
bFirst = false; ?A=b6Um  
read_nPos(); 4^Qi2[w  
} 'qeP6}M  
else y,C!9l  
{ >Gd.&flSj  
nStartPos = new long[bean.getNSplitter()]; u]vPy ria  
nEndPos = new long[bean.getNSplitter()]; k'13f,o}  
} Y5TS>iEE]  
swr"k6;G  
2bQ/0?.).-  
s"mFt{Y  
} H:}}t]E  
DnyYMe!r  
`q?RF+  
public void run() +mWjBY  
{ *re 44  
//获得文件长度 7c1+t_Ew  
//分割文件 8GB]95JWwp  
//实例FileSplitterFetch ;<6"JP>0  
//启动FileSplitterFetch线程 D u_$C[  
//等待子线程返回  v4<j   
try{ Zw=G@4xoU  
if(bFirst) .j 'wQ+_  
{ w!,QxrOV~  
nFileLength = getFileSize(); D$pj#  
if(nFileLength == -1) wa?+qiWnrl  
{ b~w KF0vq  
System.err.println("File Length is not known!"); nk08>veG  
} (KF7zP  
else if(nFileLength == -2) "\T"VS^pd  
{ `7B14:\A  
System.err.println("File is not access!"); fEiJ~&{&  
} _Xh=&(/8@  
else sco uO$K  
{ "Gh#`T0#a  
for(int i=0;i<nStartPos.length;i++) &c^7O#j  
{ m#ad6 \  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); A~y VYC6l  
} R 7K  
for(int i=0;i<nEndPos.length-1;i++) [b`$\o'-  
{  q6)N*?  
nEndPos = nStartPos[i+1]; NG-`ag`s  
} YRa4W.&Yn  
nEndPos[nEndPos.length-1] = nFileLength; [t}):}~F|  
} 2]Fu 1  
} 6Kht:WE  
O]_={%   
=YoTyq\  
//启动子线程 sMJ#<w}Q  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g\J)= ,ju,  
for(int i=0;i<nStartPos.length;i++) )+B=z}:Nfz  
{ GMb!Q0I8  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W:B}u\)C  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), = o+7xom  
nStartPos,nEndPos,i); @^HwrwRA  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); RK3.-  
fileSplitterFetch.start(); Oy'0I,  
} _W+Q3Jx-(  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $~o3}&az  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^Ezcy?  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", R<j<. h  
nEndPos = " + nFileLength); N l|^o{#  
// fileSplitterFetch[nPos.length-1].start(); z|%Bh  
o}!&y?mp  
e[p^p!a  
//等待子线程结束 W9jNUZVXE#  
//int count = 0; :~r#LRgc  
//是否结束while循环 Ph"iX'J  
boolean breakWhile = false; 3:O+GQ*  
W :>J864!  
mS7E_A8  
while(!bStop) wy\o*P9mG)  
{ ]-rczl|o  
write_nPos(); EFNdiv$wF  
Utility.sleep(500); Fj3^ #ly  
breakWhile = true; VS%@)sI|Z  
hs,5LV)|y  
r&/D~g\"|[  
for(int i=0;i<nStartPos.length;i++) Si[eAAd' :  
{ $l43>e{E  
if(!fileSplitterFetch.bDownOver) v['AB4  
{ 1l~.R#WG&  
breakWhile = false; PIpWa$b  
break; nO:HB.&@  
} CH#kvR2  
} ZK!4>OuH`  
if(breakWhile) / (.'*biQ  
break; /J8o_EV  
q4zSS #]A  
nYgx9Q"<om  
//count++; gm}C\q9  
//if(count>4) FBbm4NB  
// siteStop(); &BTfDsxAK  
} B~BUW WMfp  
.yG8B:7N2  
{;;eOxOP|  
System.err.println("文件下载结束!"); \hu':@}  
} 8}J(c=4Gk  
catch(Exception e){e.printStackTrace ();} i!y\WaCp  
} d^_itC;-,  
f0g6g!&gf  
=X<)5IS3  
//获得文件长度 xz="|HD);  
public long getFileSize() BMe72  
{ myffYK,  
int nFileLength = -1; T+3k$G[e/  
try{ 3me<~u  
URL url = new URL(siteInfoBean.getSSiteURL()); $<14JEU  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); XuA0.b%  
httpConnection.setRequestProperty("User-Agent","NetFox"); e ^-3etx  
ul}4p{ m[  
vN' VDvVM  
int responseCode=httpConnection.getResponseCode(); O} (E(v  
if(responseCode>=400) |#!eMJ&0  
{ ./2Z?,  
processErrorCode(responseCode); ]+FX$+H/A0  
return -2; //-2 represent access is error #fJwC7  4  
} N.k+AQb  
S54gqc1S]  
rR3m' [  
String sHeader; EF0Pt  
`g2&{)3k  
6{lG1\o  
for(int i=1;;i++) '=-s1c@^  
{ b^+Fs  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7B VXBw  
//Utility.log(in.readLine()); aKa  R  
sHeader=httpConnection.getHeaderFieldKey(i); 1+VY><=n  
if(sHeader!=null) ]gjr+GV  
{ *c!;^Qyp&  
if(sHeader.equals("Content-Length")) aGdpec v  
{ Qs~d_;  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6zELe.tq  
break; AfuXu@UZ_/  
} nmTm(?yE  
} Q|6Ls$'$  
else =I %g;YK  
break; z0=Rp0_W  
} rwasH,+  
} Sa( yjF1  
catch(IOException e){e.printStackTrace ();} z%++\.g_  
catch(Exception e){e.printStackTrace ();} X!7 c zt  
Omp i~  
"m wl-=  
Utility.log(nFileLength); >SY 2LmV'a  
hwEZj`9  
(R9QBZP5  
return nFileLength; m+;B!4 6  
} (rau8  
&Bj,.dD/a  
TXZ(mj?  
//保存下载信息(文件指针位置) 49iR8w?k  
private void write_nPos() *1 n;p)K  
{ VyB\]EBu  
try{ -G(3Y2  
output = new DataOutputStream(new FileOutputStream(tmpFile)); l{M;PaJ`}  
output.writeInt(nStartPos.length); )Ix-5084  
for(int i=0;i<nStartPos.length;i++) @>qx:jx(-S  
{ D|u^8\'.  
// output.writeLong(nPos); UIC\CP d  
output.writeLong(fileSplitterFetch.nStartPos); +,ZU TG  
output.writeLong(fileSplitterFetch.nEndPos); H5 p}Le  
} y|&.v <  
output.close(); ]}UeuF\  
} yEMX`  
catch(IOException e){e.printStackTrace ();} !D.= 'V  
catch(Exception e){e.printStackTrace ();} i}v}K'`  
} 7.w *+Z>z  
*u:;:W&5y  
;:#?~%7>  
//读取保存的下载信息(文件指针位置) 1(#*'xR  
private void read_nPos() b#?ai3E  
{  =F",D=  
try{ +0oyt?  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); c4!c_a2pS  
int nCount = input.readInt(); z 'vdC  
nStartPos = new long[nCount]; Tx|SAa=V  
nEndPos = new long[nCount]; v^ y}lT  
for(int i=0;i<nStartPos.length;i++) ,(;p(#F>  
{ 7eaA]y~H  
nStartPos = input.readLong(); yDu yMt#  
nEndPos = input.readLong(); > {'5>6u  
} #;qFPj- v  
input.close(); doxdRYKL  
} 7 K;'7  
catch(IOException e){e.printStackTrace ();} P3,Z5|)  
catch(Exception e){e.printStackTrace ();} X~IRpzC  
} t  z +  
J_y<0zF**  
(`q6G d  
private void processErrorCode(int nErrorCode) -z>Z0viA  
{ _rWM]  
System.err.println("Error Code : " + nErrorCode); c5T~0'n  
} {UV<=R,E  
Lic{'w&  
<Y}"D Yt  
//停止文件下载 Ti9:'I  
public void siteStop() ZTgAZ5_cz  
{ ;*<{*6;=?  
bStop = true; MHpL$g=5_  
for(int i=0;i<nStartPos.length;i++) %~~z96(  
fileSplitterFetch.splitterStop(); n6}E4Eno  
l1+w2rd1  
rC1qGzg\a  
} zezofW]a  
} Y1yvI  
//负责部分文件的抓取 $~w@0Yl  
**FileSplitterFetch.java 34+)-\xt:  
*/ yP<:iCY  
package NetFox; G>_42Rp  
(d5vH)+ A  
N>cp>&jV  
import java.io.*; -6em*$k^  
import java.net.*; X d19GP!  
[pRVZV  
: e0R7sj  
public class FileSplitterFetch extends Thread { G]m[ S-  
*1ID`o  
;S{Ld1;  
String sURL; //File URL O>b&-U"R  
long nStartPos; //File Snippet Start Position m"?' hR2  
long nEndPos; //File Snippet End Position \U<F\i  
int nThreadID; //Thread's ID k Nf!j  
boolean bDownOver = false; //Downing is over U:pLnNp`  
boolean bStop = false; //Stop identical fRv S@  
FileAccessI fileAccessI = null; //File Access interface :) Fp B"  
O_ s9  
b Q9"GO<X  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Us@ {w`T  
{ Gg3?2h"d  
this.sURL = sURL; ~' Qpf 8)  
this.nStartPos = nStart; ^%4( %68  
this.nEndPos = nEnd; mNBpb}  
nThreadID = id; x jP" 'yU  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "$,}|T?Y`  
} NBbY## w0  
@tjZvRtZ  
2o s6c te  
public void run() )z*$`?)k  
{ 7Y @=x#  
while(nStartPos < nEndPos && !bStop) 9rf|r 3  
{ )@lo ';\  
@$b+~X)7  
um_M}t{  
try{ !w;A=  
URL url = new URL(sURL); v#<+n{B  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ./BP+\)l O  
httpConnection.setRequestProperty("User-Agent","NetFox"); *~t$k56  
String sProperty = "bytes="+nStartPos+"-"; +hKPOFa'  
httpConnection.setRequestProperty("RANGE",sProperty); [ ;3EzZL  
Utility.log(sProperty); ru6HnLhL  
t+4%,n f_1  
gS(: c .  
InputStream input = httpConnection.getInputStream(); 9q0,K" x)  
//logResponseHead(httpConnection); -SC2Zgi)A  
1 [~|  
x1hs19s  
byte[] b = new byte[1024]; QF.wtMGF&  
int nRead; Z+"E*  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )8N)Z~h  
{ ^B"_b?b  
nStartPos += fileAccessI.write(b,0,nRead); tWX+\ |  
//if(nThreadID == 1) 2AdHj&XE  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )l!&i?h%  
} xUYN\Pc-  
+G=C~X  
8L9S^ '  
Utility.log("Thread " + nThreadID + " is over!"); D^R! |K/  
bDownOver = true; HNHhMi`w  
//nPos = fileAccessI.write (b,0,nRead); t&Y^W <  
} V@+<,tjq  
catch(Exception e){e.printStackTrace ();} H @&"M%  
} >* Qk~kv<%  
} BS<>gA R;/  
E<m"en&v  
Dk{nOvZu<  
//打印回应的头信息 Vo9)KxR  
public void logResponseHead(HttpURLConnection con) abk:_  
{ @l6 dJ  
for(int i=1;;i++) C7*Yg$`{  
{ B=RKi\K6a  
String header=con.getHeaderFieldKey(i); G3?a~n^b  
if(header!=null) s)7`r6w  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )dN,b( w9  
Utility.log(header+" : "+con.getHeaderField(header)); 8KdcLN@  
else  d7-F&!sQ  
break; aid)q&AcQ  
} 5A=xFj{  
} !E>3N:  
"F.J>QBd  
O 9 Au =  
public void splitterStop() ^MWW,`  
{ &B5 Rzz-'  
bStop = true; CYic_rF$  
} \?mU$,v oI  
NNpa69U  
G?/8&%8  
} 1.OXkgh  
T.Y4L  
TX5/{cHd  
/* zm^p7&ak$  
**FileAccess.java N@`9 ~JS  
*//文件访问(定位,写) v_ F?x!  
package NetFox; {~p %\  
import java.io.*; x?k |i}Q  
bA9dbe  
P*^UU\x'4I  
public class FileAccessI implements Serializable{ GMp'KEQQ  
H(ftOd.y  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %KVRiX  
RandomAccessFile oSavedFile; 5>k~yaju/  
long nPos; <HX-qNA?  
[(^''*7r+T  
HBkQ`T  
public FileAccessI() throws IOException GISI8W^  
{ 6 VJj(9%  
this("",0); 21J82M  
} l[j0(T  
K0!#l Br  
` ];[T=  
public FileAccessI(String sName,long nPos) throws IOException 9(Xch2tpO!  
{ Fl(ZKpSZU  
oSavedFile = new RandomAccessFile(sName,"rw"); 5TW<1'u  
this.nPos = nPos; $G([#N<  
oSavedFile.seek(nPos); gmH0-W)=  
} HE .Dl7 {  
Qz90 mb  
!{=%l+^.  
public synchronized int write(byte[] b,int nStart,int nLen) rlh6\Fa  
{ g<jK^\e W  
int n = -1; -Y,Ibq  
try{ 4'eVFu+62  
oSavedFile.write(b,nStart,nLen); leqSS}KU+  
n = nLen; j W]c9u  
} ^\t">NJ^  
catch(IOException e) ]V7hl#VO  
{ *>H'@gS  
e.printStackTrace (); ~bQ:gArk  
} 8k}CR)3@C  
\A"a>e  
9jFDBy+  
return n; L.&Vi"M <@  
} Gi_X+os  
~x#-#nuh"  
t-{OP?cE1  
} jS)-COk  
)n61IqrW  
c^UM(bW  
/* fO|u(e  
**SiteInfoBean.java XSIO0ep  
*/ Ppn ZlGQ6  
package NetFox; E)SOcM)  
d`*vJ#$> 2  
ApB'O;5  
public class SiteInfoBean { m`6`a|Twp$  
5w%9b  
e/l?|+m 6  
private String sSiteURL; //Site's URL 9GOyVKUv  
private String sFilePath; //Saved File's Path _C\ d^a (  
private String sFileName; //Saved File's Name o[*ih\d  
private int nSplitter; //Count of Splited Downloading File eh=bClk  
nr%^:u  
,$*klod  
public SiteInfoBean() o{,(`o.1O  
{//nSplitter的缺省值为5 AYtcN4\/  
//default value of nSplitter is 5 U}5KAi 9Z  
this("","","",5); |-?b)yuAz  
} c'4 \F9  
~0  t'+.  
jDR\#cGrZ  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 35\0g&  
{ :~(^b;yhZ  
sSiteURL= sURL; rJ*WxOoS{  
sFilePath = sPath; C!A_PQ2y  
sFileName = sName; pfIvBU?  
this.nSplitter = nSpiltter; SQRz8,sqkw  
+4RaN`I  
<AXYqH7%A  
} !S<~(Ujyw  
x@x@0k`A2  
sVf7g?  
public String getSSiteURL() \p|!=H@  
{ VdrF=V&] O  
return sSiteURL; Sa(r l^qZ2  
} 7tnzgtal  
`fHiY.-  
:"^$7  
public void setSSiteURL(String value)  HuC lO  
{ |1x,_uyQ%  
sSiteURL = value; @TT[H*,  
} Gj0NN:  
1 1'Tt!  
 6<GWDO  
public String getSFilePath() a_x6 v*  
{ 9dv~WtH>5  
return sFilePath; 247>+:7z  
} M>#S z  
L*38T\  
)HHzvGsL)  
public void setSFilePath(String value) S]{Z_|h*j  
{ :@L5=2Z+  
sFilePath = value; Gj?q+-d!(5  
} ]].21  
O2B$c\pw  
r3)t5P*_  
public String getSFileName() %dQX d ]  
{ w,$17+]3  
return sFileName; z AIC5fvu  
} S^.=j oI  
YEj U3^@  
LdL\B0^l  
public void setSFileName(String value) mLqm83  
{  O@$i  
sFileName = value; C\[UAxZ3X  
} &kE|~i:=,9  
C?J%^?v  
hkxZ=l  
public int getNSplitter() /J:j'6  
{ XDQ1gg`  
return nSplitter; YKk%;U*  
} ]QQ"7_+  
NI)nf;C  
F'!}$oT"  
public void setNSplitter(int nCount) 03y<'n  
{ .?TVBbc%5  
nSplitter = nCount; \k8_ZJw  
} 5{[0Clb)  
} dWSH\wm+  
.BvV[`P  
IU}`5+:m  
/* :|TBsd|/x  
**Utility.java $+j )  
*/ 3{=4q  
package NetFox; MJoC*8QxM  
~]Jfg$'  
fQh!1R  
public class Utility { ,#{aAx|]  
<o O_wS@:  
&iivSc;#  
public Utility() !k^\`jMzw  
{ 'UKB pm/  
Nt?B(.G  
b7/4~_s  
} ZhU2z*qN#  
(A_9;uL^_  
//线程睡眠 >E#4mm  
public static void sleep(int nSecond) uNjy&I:  
{ Q]C1m<x  
try{ ijfT!W  
Thread.sleep(nSecond); mvxvX!t  
} I nk76-  
catch(Exception e)  R !HL+  
{ `7`iCYiTy  
e.printStackTrace (); 191)JWfa  
} .'M]cN~  
} a>6p])Wh  
\uH;ng|m  
//日志 Rh|&{Tf  
public static void log(String sMsg) ek<U2C_u#  
{ z!tHn#  
System.err.println(sMsg); t<-Iiq+tL  
} $= gv  
d>f5T l\E  
~rD* Y&#.  
public static void log(int sMsg) I`7[0jA~  
{ }j x{Cw  
System.err.println(sMsg); ESAh(A)8  
} y!j1xnzki  
} \BA_PyS?W+  
(Y%}N(Jg  
EW)]75o{QF  
/* LdcP0G\"VG  
**TestMethod.java ,fbO}  
*/ xYbF76B  
package NetFox; HDYoM  
G7u7x?E:B`  
YAD9'h]d\  
public class TestMethod { G 8@%)$A  
F-m1GG0s  
y9 "!ys  
public TestMethod() zPn8>J<.0Q  
{ ///xx/weblogic60b2_win.exe zT@vji%Y  
try{ mYZH]oo  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 'yl`0,3wV  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); SRMy#j-  
SiteFileFetch fileFetch = new SiteFileFetch(bean); $%/Zm*H  
fileFetch.start(); 1mf_1spB  
} fE >FT9c  
catch(Exception e){e.printStackTrace ();} &A>J>b  
-1[ri8t;nV  
=d 9%ce  
} ]0o78(/w2  
T ^uBMDYe  
*<KY^;  
public static void main(String[] args) Li}yK[\]  
{ nG2RBeJV  
new TestMethod(); *%8dW  
} FBe 1f1 sm  
} v+Hu=RZE  
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