http断点续传简单实现（java)

/* #3knKBH  
**SiteFileFetch.java 1c\KRK4  
*/ jct|}U  
package NetFox; Ur9L8EdC  
import java.io.*; 8=MNzcA }  
import java.net.*; PjG^L FX  
H~NK:qRzK  
0-Ga2Go9  
public class SiteFileFetch extends Thread { =91wC  
wgUgNwd1  
kNd(KQ<.17  
SiteInfoBean siteInfoBean = null; //文件信息Bean ^wIg|Gc  
long[] nStartPos; //开始位置 64UrD{$o  
long[] nEndPos; //结束位置 oTN:Q"oK7?  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 z&c|2L-u6  
long nFileLength; //文件长度 ]3Y J a  
boolean bFirst = true; //是否第一次取文件 QOR92}yC  
boolean bStop = false; //停止标志 /O}lSXo
6E  
File tmpFile; //文件下载的临时信息 : i{tqY%  
DataOutputStream output; //输出到文件的输出流 iLt2L;v>h  
j  Gp&P  
//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） 8n,/hY>w  
public SiteFileFetch(SiteInfoBean bean) throws IOException 5wa'Sexq
E  
{ LC,6hpmh  
siteInfoBean = bean; Bra}HjHO  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); -#Ys67,4N  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); JJHO E{%  
if(tmpFile.exists ()) ()Q#@?c~  
{ %"Ia]0  
bFirst = false;
(M2hK[  
read_nPos(); M?_7*o]!  
} P84=.*>  
else %-KgR  
{ w `nm}4M  
nStartPos = new long[bean.getNSplitter()]; qi*Dd[OG  
nEndPos = new long[bean.getNSplitter()]; &n'@L9v81  
} IhHKRb[  
wq7h8Z}l  
V!Pe%.>  
@u@,Edh  
} ,4j^lgJ  
E?0Vo%Vh  
O2:1aG  
public void run() H+ 7HD|GE  
{ tIT/HG_o  
//获得文件长度 d=0{vsrB  
//分割文件 ,R\ex =c  
//实例FileSplitterFetch -asjBSo*D  
//启动FileSplitterFetch线程 tM|/OJ7  
//等待子线程返回 t)5.m}  
try{ BJt]k7ku+  
if(bFirst) S6<#] 6Z  
{ =h70!) Z5  
nFileLength = getFileSize(); DYF(O-hJK  
if(nFileLength == -1) {DD #&B  
{ "%YVAaN  
System.err.println("File Length is not known!"); P(.XB`  
} ;@*<M
\O  
else if(nFileLength == -2) {%\@Z-9%q,  
{ *nK4XgD  
System.err.println("File is not access!"); n/{ pQ&B  
} V a
oqI  
else ,A5}HRW%  
{ ?kK3%uJy&  
for(int i=0;i<nStartPos.length;i++) {9FL}Jrt  
{ x];i? 4  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 6:q,JB@i  
} 5@J]#bp0M  
for(int i=0;i<nEndPos.length-1;i++) ~3Za"q*0s  
{ HB,?}S#TP  
nEndPos = nStartPos[i+1]; TBIr^n>Z<k  
} VU1Wr|  
nEndPos[nEndPos.length-1] = nFileLength; "g*`G<W_s  
} K 6yD64  
} yIC C8M  
I Z|EPzS  
<iBn-EG l>  
//启动子线程 `
oTV)J'~  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; CTe!jMZ=  
for(int i=0;i<nStartPos.length;i++) ;Y,zlq2  
{ e8E'X  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(),
XmaRg{22  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), S5:&_&R8[  
nStartPos,nEndPos,i);
8>9MeDE  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $DaQM'-  
fileSplitterFetch.start(); :r2d%:h%2  
} }KYOde@  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(),
voFg6zoV_  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); kxR!hA8wv4  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", v cUGBGX_&  
nEndPos = " + nFileLength); dO
K]Su  
// fileSplitterFetch[nPos.length-1].start(); )5`~WzA  
4M!wm]n/%5  
DS9-i2  
//等待子线程结束 Q-B/SX)!/  
//int count = 0; Y_6v@Si
O  
//是否结束while循环 hE E1i  
boolean breakWhile = false; oJ tmd}  
;<*%BtD?  
?-~<Vc*  
while(!bStop) }(!rB#bf  
{ 3kT?Y7<fv  
write_nPos(); PI@?I&
Bo  
Utility.sleep(500); A<^X P-Nrp  
breakWhile = true; (! 8y~n1  
cE>m/^SKr  
AiL80W^=d)  
for(int i=0;i<nStartPos.length;i++) iJeodfC  
{ s)?GscPG!  
if(!fileSplitterFetch.bDownOver) }]M'f:%b  
{ \=P(?!v  
breakWhile = false; V(XZ7<& {  
break; kT]jJbb"  
} ]0O3kiVQ  
} Q{5.;{/eC  
if(breakWhile) ~Q#!oh'i  
break; H )>3c1  
lWH#/5`h  
_#Lq~02 %  
//count++; ]t~'wL#Z  
//if(count>4) Mnk-"d  
// siteStop(); ,c0t#KgQ.  
} E3(o}O  
Vc6 >i|"-O  
+*Fe   
System.err.println("文件下载结束！"); D>^g2!b:  
} EM@EB<pRX  
catch(Exception e){e.printStackTrace ();} H!6+x*P
0  
} (sI`FW_  
hT,rcIkg:  
yJ`{\7Uqg  
//获得文件长度 y>:U&P^  
public long getFileSize() ^O=G%de  
{
cs_  
int nFileLength = -1; M6 8foeeN  
try{ L0I|V[  
URL url = new URL(siteInfoBean.getSSiteURL()); <CJy3<$u  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GIT"J}b}  
httpConnection.setRequestProperty("User-Agent","NetFox"); ,
6#%+u}f  
[$uKI,l  
k7{|\w%  
int responseCode=httpConnection.getResponseCode(); c<lEFk!g
 
if(responseCode>=400) _mk@1ft  
{ 6tjV^sjs  
processErrorCode(responseCode); }#
;.b'`  
return -2; //-2 represent access is error K<r5jb  
} Um4DVg5  
wv\V&U$  
$iMLT8U  
String sHeader; ;;m;f^]}  
DSWmQQ  
?Ok&,\F@E  
for(int i=1;;i++) {-MjsBR  
{ fFoZ!H  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); `KE]RTq  
//Utility.log(in.readLine()); -/0aGqY  
sHeader=httpConnection.getHeaderFieldKey(i); QN?EI: q=  
if(sHeader!=null) j:>0XP  
{ 4.uaWM)2  
if(sHeader.equals("Content-Length")) e2K9CE.O  
{ &cd>.&1<2  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); p@Cas  
break; T$AVMVq  
} A0RSNAM  
} FzP1b_i  
else 2`%a[t@M.  
break; hg:$H9\%  
} K3UN#G
)U  
} C@\5%~tW+  
catch(IOException e){e.printStackTrace ();} 0*9xau{(  
catch(Exception e){e.printStackTrace ();} ho B[L}<c  
nz'6^D7`r  
KF5r?|8M  
Utility.log(nFileLength); @|sBnerE  
,!LY:pMK  
U* c'xoP  
return nFileLength; Fq!_VF^r  
} ,Vo[mB  
H3`.Y$z  
~'0ZW<X.  
//保存下载信息（文件指针位置） ].5q,A]  
private void write_nPos() *9w-eK1{  
{ r{84Y!k~*  
try{ x,cvAbwS  
output = new DataOutputStream(new FileOutputStream(tmpFile)); c`UFNNm=  
output.writeInt(nStartPos.length); 5W&L cBB  
for(int i=0;i<nStartPos.length;i++) z]C=nXbk  
{ 3:8p="$F  
// output.writeLong(nPos); '-J<ib t  
output.writeLong(fileSplitterFetch.nStartPos); r:g
_mMvB  
output.writeLong(fileSplitterFetch.nEndPos); zUNUH^Il  
} _h1eW9q  
output.close(); ](8F]J ,  
} 1|!)*!hu  
catch(IOException e){e.printStackTrace ();} %l#X6jkt  
catch(Exception e){e.printStackTrace ();} P,a9B2  
} Q4/BpKL  
&zJ\D`\,O  
S-ZN}N{,6  
//读取保存的下载信息（文件指针位置） m[iQ7/  
private void read_nPos() md? cvGDE  
{ .pdcwd9  
try{ #$W0%7  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); l 9g  
int nCount = input.readInt(); ?G!~&  
nStartPos = new long[nCount]; ?8?vBkz~  
nEndPos = new long[nCount]; O"df5x9@  
for(int i=0;i<nStartPos.length;i++) rnQ_0d  
{ X9SOcg3a  
nStartPos = input.readLong(); ;ND[+i2MN  
nEndPos = input.readLong(); ^OX}y~'  
} p >ua{}!L  
input.close(); -*~ @?  
} vfvp#  
catch(IOException e){e.printStackTrace ();} sf[|8}(  
catch(Exception e){e.printStackTrace ();} 42A'`io[w]  
} Y'bz>@1(  
f-|zh#L  
j;V\~[I^u  
private void processErrorCode(int nErrorCode) zJl;|E".  
{ ,EVPnH[F~  
System.err.println("Error Code : " + nErrorCode); `-{? !  
} k9<UDg_ Y  
E i>GhvRM  
WiB~sIp  
//停止文件下载 u0,QsD)_X0  
public void siteStop() V9qA'k  
{ Oq,@{V@)9k  
bStop = true; >;Vfs{Z(q  
for(int i=0;i<nStartPos.length;i++) &7>]# *  
fileSplitterFetch.splitterStop(); *| W*Mu  
+F8K%.Q_  
s3yGL  
} Skr0WQ  
} Yt,MXm\  
//负责部分文件的抓取 ^Go,HiB  
**FileSplitterFetch.java Fw{#4  
*/ dT% eq7=  
package NetFox; BBGub?(dR  
s]0 J'UN  
mCk_c  
import java.io.*; Hm
!"%  
import java.net.*; ;~djbo0,X  
Uf]$I`T#  
nTD%i~t~o  
public class FileSplitterFetch extends Thread { MMC$c=4"  
QA;,/iw`  
G3+e5/0  
String sURL; //File URL FE{c{G<  
long nStartPos; //File Snippet Start Position `w`N5 !  
long nEndPos; //File Snippet End Position QKx(S=4jQ  
int nThreadID; //Thread's ID o#1Ta7Ro  
boolean bDownOver = false; //Downing is over &"gX 7cK8  
boolean bStop = false; //Stop identical b
c~$"  
FileAccessI fileAccessI = null; //File Access interface 9&Un|cr  
T+zhj++  
TbT/ 5W3  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8-7Ml3G*  
{ $ta JVVF  
this.sURL = sURL; 4&%H;Q  
this.nStartPos = nStart; \}u/0UF97  
this.nEndPos = nEnd; , %8)I("  
nThreadID = id; p{W Amly  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ?I?~BWu  
} D|m0Vj b  
qC"`i}7  
#I.~+M  
public void run() }vx,i99W?  
{ $joGda  
while(nStartPos < nEndPos && !bStop) fp\mBe
i  
{ YQFz6#Ew  
R@5eHP^  
DNgh#!\X  
try{ wb(S7OsMO  
URL url = new URL(sURL); s_RK x)w@  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dhxzW@'nIL  
httpConnection.setRequestProperty("User-Agent","NetFox"); }fkdv6mz  
String sProperty = "bytes="+nStartPos+"-"; ,Nhv#U<$  
httpConnection.setRequestProperty("RANGE",sProperty); E3[9!L8gb  
Utility.log(sProperty); Pi |Z\j)  
?u:mscb  
HWB\}jcA6u  
InputStream input = httpConnection.getInputStream(); )4s7,R  
//logResponseHead(httpConnection); !v=/f_6  
@&&}J  
iHf):J?8 y  
byte[] b = new byte[1024]; ^>!&]@  
int nRead; *S}CiwW>/  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )m8Gbkj<  
{ k}E_1_S(  
nStartPos += fileAccessI.write(b,0,nRead); 0F![<5X  
//if(nThreadID == 1) qNHI$r'  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l<4P">M!.  
} ~,KrL(jC  
%3TioM[B  
.>[l@x"  
Utility.log("Thread " + nThreadID + " is over!"); Cg~1<J?2  
bDownOver = true; oq,nfUA  
//nPos = fileAccessI.write (b,0,nRead); /F"eqMN  
} I0Allw[  
catch(Exception e){e.printStackTrace ();} fJ5mKN  
} y4|<+9<7  
} ^'
tT_ gT  
>@cBDS<6R  
8%YyxoCH  
//打印回应的头信息 M=ag\1S&ZF  
public void logResponseHead(HttpURLConnection con) fK]%*i_"  
{ CMbID1M3  
for(int i=1;;i++) |.yS~XFJS  
{ pCo3%(  
String header=con.getHeaderFieldKey(i); lfCr`[!E  
if(header!=null) ;/wH/!b  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); z^T;d^OJc  
Utility.log(header+" : "+con.getHeaderField(header)); nHDKe)V  
else !s/qqq:g  
break; Qnt}:M+  
} "K9[P:nw  
} !O`j  
8mRZ(B>% X  
oHv.EO  
public void splitterStop() :eD-'#@$u  
{ /4+Q; P  
bStop = true; na9YlJ\  
} \<xo`2b  
)16+Pm8  
3WwCo.q;m  
} us1$  
<"`f!k#[  
Ci4c8  
/* J@<f*  
**FileAccess.java %(6+{'j~#  
*//文件访问(定位，写) LE5N2k  
package NetFox; :%Iv<d<  
import java.io.*; J"GsdLG.-  
gpzFY"MS=  
|&-*&)iD|w  
public class FileAccessI implements Serializable{ D$H&^,?N  
''q;yKpaz  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 F 2zUz[  
RandomAccessFile oSavedFile; X6$Cd]MN  
long nPos; HOH5_E>d  
;=^J_2ls  
83_mR*tGNp  
public FileAccessI() throws IOException \8\TTkVSq  
{ 3*j1v:x`  
this("",0); CH!\uK22  
} nm%qm  
c2
:
,  
e&8Meiv+d  
public FileAccessI(String sName,long nPos) throws IOException NRP)'E  
{ lFcHE c  
oSavedFile = new RandomAccessFile(sName,"rw"); dxZn| Y  
this.nPos = nPos; Gl3g.`X{$@  
oSavedFile.seek(nPos); (vi^ t{k  
} DoO ;VF  
f>cUdEPBb  
|?^N@  
public synchronized int write(byte[] b,int nStart,int nLen) lB/^  
{ ;*F
Y+jM  
int n = -1; |9$C%@8  
try{ Yc~lYz+b  
oSavedFile.write(b,nStart,nLen); z(O*DwY#  
n = nLen; *0L3#. i  
} A0;{$/  
catch(IOException e) fU%Ys9:wU  
{ };"_Ku4#-  
e.printStackTrace (); QZ7W:%r(4  
} Xa;wx3]t  
"7Kw]8mRR  
;QCGl$8A  
return n; =u0a/2u|  
} VJW8%s[  
@V1FBw9S!@  
Ygg(qB1q  
} QKvaTy#  
A(BjU:D(Oj  
?aBAmyxm  
/* [5-IkT0  
**SiteInfoBean.java g26_#4 P  
*/ pBBKfv  
package NetFox; ;Z"Iv  
iGj
,B =35  
rAW7Zp~KK  
public class SiteInfoBean { ;H71A[M T  

|FlB#  
L.K|]]u  
private String sSiteURL; //Site's URL a5pM~.]  
private String sFilePath; //Saved File's Path Pjvb}q=  
private String sFileName; //Saved File's Name eL)m(  
private int nSplitter; //Count of Splited Downloading File 'h~IbP  
l9+CJAmq  
CV{ZoY  
public SiteInfoBean() :U'n0\  
{//nSplitter的缺省值为5 VB8eGMo  
//default value of nSplitter is 5 &\6(iL  
this("","","",5); SLNOOEN  
} ]0%{IgB  
3&c'3y:b  
^:f)XZ  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "iK'O =M  
{ :(3'"^_NA  
sSiteURL= sURL; &n83>Q  
sFilePath = sPath; RCK*?\m5  
sFileName = sName; Y}yh6r;i  
this.nSplitter = nSpiltter; 3w[uc~f  
|@R/JGB^  
&lzCRRnvt  
} tN.BI1nB  
,5t_}d|3C=  
$SFreyI;Uf  
public String getSSiteURL() ]eFNR1<OP  
{ km lb,P  
return sSiteURL; a #p`l>rx  
} X ) =-a  
aGE} EK}  
KiC,O7&<  
public void setSSiteURL(String value) c1*^ \  
{ @&Yl'&pn-R  
sSiteURL = value; !>K=@9NC|.  
} Dp} $q`F[  
~\u>jel  
Z~|%asjFE  
public String getSFilePath() ~WB-WI\  
{ #q&Nd2y  
return sFilePath; k#mL4$]V5N  
} UA0( cK  
k4:=y9`R}$  
bsI?=lO  
public void setSFilePath(String value) YVz,P_\(m  
{ SST@   
sFilePath = value; ^tjM1uaZ5(  
} =PjdL32  
>%t5j?p  
i8R2Y9Q*O  
public String getSFileName() lqAv  
{ Nlc3S+$`z  
return sFileName; NcSi%]  
} .)FFl  
^fS_h`B  
XwU1CejP0  
public void setSFileName(String value) n4+^f~Y  
{ _71I9V&  
sFileName = value; w>RwEU+w=@  
} =fhRyU:C[z  
D42!#  
|*]<*qnZt  
public int getNSplitter() p8&rl|z|  
{ 6"+bCx0:  
return nSplitter; Zjc0R   
} !|"LAr9u  
"QtkNy%E  
`<R^ZL,  
public void setNSplitter(int nCount) -Zg@#H  
{ }72+i  
nSplitter = nCount; r6 pz(rCs}  
} SvQj'5~<  
} ^Ri ; vM  
A_J!VXq  
Nlm3RxSn  
/* o1&Oug  
**Utility.java c&SSf_0O*  
*/ Y#U0g|UDn  
package NetFox; W[73q>'  
7Uh/Gl  
N\hHu6  
public class Utility { h>|IA@;|f  
P>*`<$FR  
`DP4u\6_  
public Utility() {E1^Wn1M  
{ x$b
Cbg  
H
|;BT  
3J^'x  
} jrYA5>=>#  
0IbR>zFg.  
//线程睡眠 
oi^pU  
public static void sleep(int nSecond) @CCDe`R*  
{ sbFA{l3  
try{ Reg%ah|$/=  
Thread.sleep(nSecond); R&L^+?  
} ,L(q/#p
  
catch(Exception e) +C=^,B!,  
{ 1-pxM~Y  
e.printStackTrace (); tW3Nry  
} o{K#LP  
} 1tCe#*|95  
nqib`U@"  
//日志 ~_4$|WKl  
public static void log(String sMsg) {'f=*vMI  
{ MrS~u  
System.err.println(sMsg); gJ5|P .  
} nrz2f7d$  
59a7%w  
Jn1(-  
public static void log(int sMsg) vnv:YQV/ir  
{ 2&:w_KJ  
System.err.println(sMsg); _^]:tL6  
} XZpF<7l  
} ~5_>$7L>  
8lT2qqlr  
*W1:AGpz  
/* e5m-7{h@  
**TestMethod.java /A%31WE&1  
*/ DI:"+KMq{  
package NetFox; !}&f2!?.W  
^36m$J$  
0BHSeO,  
public class TestMethod { ]}N&I_mU  
uJt*> ;Kp  
.!h`(>+@  
public TestMethod() "@+r|x  
{ ///xx/weblogic60b2_win.exe `bRt_XGPmF  
try{ os`#:Ao5  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >l0D,-O]m  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /Os;,g  
SiteFileFetch fileFetch = new SiteFileFetch(bean); @:G#[>nKe  
fileFetch.start(); L]Dl}z  
} 7T9Mo .  
catch(Exception e){e.printStackTrace ();}  *4{GID  
$pYT#_P!/  
'0E^th#u-0  
} /Es&~Fn  
PQ`~qM:3st  
oxgh;v*  
public static void main(String[] args) Z3nmC-NE  
{ x[eho,6)  
new TestMethod(); 3h>56{P  
} :~dI2e\:  
} + |d[q?  
点击下载更多相关资料