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http断点续传简单实现(java)

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/* 'zRi ;:UHA  
**SiteFileFetch.java 2 }9of[  
*/ V6c>1nZ  
package NetFox; f *Xum[  
import java.io.*; iRbTH}4i  
import java.net.*; d9j+==S <  
 #  
BLepCF38  
public class SiteFileFetch extends Thread { b]-~{' +  
h20<X;  
@Cnn8Y&'  
SiteInfoBean siteInfoBean = null; //文件信息Bean iY|zv|;]=  
long[] nStartPos; //开始位置 A`5/u"]*D  
long[] nEndPos; //结束位置 ^~p^N <  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ^| b]E  
long nFileLength; //文件长度 ?Aq \Gr  
boolean bFirst = true; //是否第一次取文件 =XRTeIZ  
boolean bStop = false; //停止标志 #hKaH -j  
File tmpFile; //文件下载的临时信息 +#B4Z'nT  
DataOutputStream output; //输出到文件的输出流 uVSc1 MS1  
\zdY$3z  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) fGwRv% $^  
public SiteFileFetch(SiteInfoBean bean) throws IOException {?!0<0  
{ y ~PW_,  
siteInfoBean = bean; =6sA49~M  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); :jKiHeBQu?  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); (plsL   
if(tmpFile.exists ()) I^u$H&  
{ k@[P\(a3b  
bFirst = false; u|.c?fW'3  
read_nPos(); $i|c6&  
} 9<" .1  
else @nh* H{  
{ ,m HQ  
nStartPos = new long[bean.getNSplitter()]; x5X;^.1Fr  
nEndPos = new long[bean.getNSplitter()]; F2N)|C<  
} 1#Ls4+]5  
J{69iQ  
D*nNu]|j  
Au=9<WB%H  
} , GU|3  
dj;Zzt3  
'XbrO|%  
public void run() n[E#K`gg'  
{ ^xNs^wC.  
//获得文件长度 hx5oTJR  
//分割文件 ]N& Y25oT5  
//实例FileSplitterFetch |riP*b  
//启动FileSplitterFetch线程 u2FD@Xq?  
//等待子线程返回 + Cf  
try{ 5PRS|R7  
if(bFirst) +L]$M)*0&  
{ _MI8P/  
nFileLength = getFileSize(); d3IMQ_k  
if(nFileLength == -1) D)_67w|u|  
{ "44A#0)B'l  
System.err.println("File Length is not known!"); iC.k8r+~  
} ; 1^ ([>|  
else if(nFileLength == -2) Eq\PSa=gz  
{ 'G#T 6B!  
System.err.println("File is not access!"); XMLJ X~  
} 8M~^/Zc  
else f ecV[  
{ r](%9Y  
for(int i=0;i<nStartPos.length;i++) &yabxl_  
{ -aV!ZODt  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); !Z}d^$  
}  45qSt2  
for(int i=0;i<nEndPos.length-1;i++) Nr(t5TP^  
{ Rn4Bl8z'>  
nEndPos = nStartPos[i+1]; 2BGS$$pP  
} }j_2K1NS{  
nEndPos[nEndPos.length-1] = nFileLength; cU[^[;4J<  
} r2xXS&9!|  
} H?a1XEY/  
V9 J`LQ\0  
W[R^5{k`  
//启动子线程 !VzbNJ&'  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !%lcn O  
for(int i=0;i<nStartPos.length;i++) uex m|5|  
{ Nj^:8]D)0  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /E32^o|,>  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), c(j|xQ\pE  
nStartPos,nEndPos,i); Bokpvd-c7  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c2o.H!>  
fileSplitterFetch.start(); F3Y/Miw  
} 4[P]+Z5b+  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |ler\"Eu  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Pqtk1=U  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", er44s^$  
nEndPos = " + nFileLength); MKPw;@-  
// fileSplitterFetch[nPos.length-1].start(); Pf/_lBtL  
]aDU*tk  
`J v~.EF%  
//等待子线程结束 S5(VdMd"^  
//int count = 0; }QzF.![~z  
//是否结束while循环 <} BuU!  
boolean breakWhile = false; *)| EWT?,  
#<k L.e[  
jY|fP!?[  
while(!bStop) Ui43&B  
{ W-8U~*/  
write_nPos(); `m_ ('N  
Utility.sleep(500); ^OZ*Le  
breakWhile = true; =K:)%Qh  
y~Ts9AE  
m~;}8ObQE  
for(int i=0;i<nStartPos.length;i++) 9[@K4&  
{ )&F]j  
if(!fileSplitterFetch.bDownOver) Q8GI;`Rb  
{ XN Gw@$  
breakWhile = false; O>tz;RU  
break; /9o gg  
} B(t`$mC  
} 5BAGIO<w  
if(breakWhile) ,CED%  
break; ,3P@5Ef  
6!T9VL\=H  
q?0&&"T}  
//count++; C>=[fAr mO  
//if(count>4) SF. Is=b  
// siteStop(); 98ot{+/LK  
} AbA_s I<;  
ah2L8jN"  
`iZ){JfAH  
System.err.println("文件下载结束!"); sogdM{tz\  
} jV 98 2Y  
catch(Exception e){e.printStackTrace ();} 'Z}3XVZEN  
} 3 [r9v!l  
/t|Lu@&:Xo  
w'Vm'zo  
//获得文件长度 < pWk   
public long getFileSize() Y=$PsDh!  
{ KSgYf;  
int nFileLength = -1; jxdX7aik  
try{ ;^f ;<  
URL url = new URL(siteInfoBean.getSSiteURL()); Usl963A#'F  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); EN-;@P9;C  
httpConnection.setRequestProperty("User-Agent","NetFox"); oU)Hco"_k  
yR$ld.[uf  
X"EZpJ'W  
int responseCode=httpConnection.getResponseCode(); X6-;vnlKN  
if(responseCode>=400) iyJx~:  
{ 6 6C_XT  
processErrorCode(responseCode); !lxq,Whr{  
return -2; //-2 represent access is error DcRvZH  
} von<I  
svRYdInBNu  
>)*0lfxTZ  
String sHeader;  \<u  
(b#4Z  
EN/r{Cm$B  
for(int i=1;;i++) SSn{,H8/j  
{ PdqyNn=  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); t->I# t7  
//Utility.log(in.readLine()); wB+X@AA  
sHeader=httpConnection.getHeaderFieldKey(i); :um]a70  
if(sHeader!=null) 1)t*l;.  
{ b<27XZ@  
if(sHeader.equals("Content-Length")) z2U^z*n{  
{ ,!vI@>nhG  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {v}BtZ  
break; V: n\skM  
} P^^WViVX  
} ,lDOo+eE%:  
else Ny5$IIF e  
break; }!QVcu"+t/  
} ksy]t |  
} BFswqp:  
catch(IOException e){e.printStackTrace ();} +lw8YH  
catch(Exception e){e.printStackTrace ();} 9?tG?b0  
srK9B0I  
dZ|x `bIgs  
Utility.log(nFileLength); Oh5aJ)"D  
8 k )i-&R  
#<DS-^W!  
return nFileLength; D9JHx+Xf>  
} 0b}.!k9  
9>r@wK'Pn  
.&2~g A  
//保存下载信息(文件指针位置) V`m9+<.1b  
private void write_nPos() h9kwyhd"  
{ gX]ewbPDQ  
try{ o[%\W  
output = new DataOutputStream(new FileOutputStream(tmpFile)); cRv#aV  
output.writeInt(nStartPos.length); lf\x`3Vd  
for(int i=0;i<nStartPos.length;i++) u;9a/RI  
{ (*Z:ByA  
// output.writeLong(nPos); p^)w$UL}}  
output.writeLong(fileSplitterFetch.nStartPos); H,EGB8E2  
output.writeLong(fileSplitterFetch.nEndPos); C#TP1~6  
} Hm'aD2k  
output.close(); ldt]=Sqy  
} CU@}{}Yl  
catch(IOException e){e.printStackTrace ();} |4rqj 1*U  
catch(Exception e){e.printStackTrace ();} \)i,`bz  
} et=i@PB)  
>%LY0(hY3  
[ d`m)MW-  
//读取保存的下载信息(文件指针位置) O!P7Wu  
private void read_nPos() "V`5 $ur  
{ ;KgDVq5  
try{ $"ACg!=M  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <"yL(s^u"  
int nCount = input.readInt(); Nx"|10gC  
nStartPos = new long[nCount]; n(W&GSj|u9  
nEndPos = new long[nCount]; kS4YxtvB  
for(int i=0;i<nStartPos.length;i++) sGx3O i   
{ VIg6'  
nStartPos = input.readLong(); U|Uc|6  
nEndPos = input.readLong(); K[S)e!\.  
} B.:1fT7lI  
input.close(); \ 027>~u {  
} j/;wxKW  
catch(IOException e){e.printStackTrace ();} }#S1!TU  
catch(Exception e){e.printStackTrace ();} fr`Q 5!0  
} a n0n8l  
xlH3t&i7  
VfwH:  
private void processErrorCode(int nErrorCode) K>TEt5  
{ mpQu:i|W  
System.err.println("Error Code : " + nErrorCode); e*Y<m\*  
} t N4-<6  
k *D8IB  
FKUo^F?z  
//停止文件下载 3taGb>15  
public void siteStop() 2R W~jn"  
{ frc9   
bStop = true; \BX9Wn*)a  
for(int i=0;i<nStartPos.length;i++) S gssNv  
fileSplitterFetch.splitterStop(); gq@8Z AWn  
}rUAYr~VZ  
K0D|p$v  
} N6`U)=2o>h  
} tu(^D23  
//负责部分文件的抓取 'bsHoO  
**FileSplitterFetch.java  O*.n;_&  
*/ 7 IJn9b  
package NetFox; d2TIG<6/  
@v3)N[|d  
efE=5%O  
import java.io.*; -9;?k{{[T  
import java.net.*; !2>@:CKX  
I9m9`4BK  
'Lw8l `7  
public class FileSplitterFetch extends Thread { d]:G#<.  
[!MS1v c;  
KuW>^mF(I  
String sURL; //File URL #c":y5:  
long nStartPos; //File Snippet Start Position Xvoz4'Gme  
long nEndPos; //File Snippet End Position 9Ofls9]U  
int nThreadID; //Thread's ID ><S(n#EB  
boolean bDownOver = false; //Downing is over v??$z#1F3  
boolean bStop = false; //Stop identical ' sNiJ>  
FileAccessI fileAccessI = null; //File Access interface &n#yxv4  
{> 8?6m-  
A\W) uwyN  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException W\j)Vg__e  
{ 9|[uie  
this.sURL = sURL; \Rb:t}  
this.nStartPos = nStart; &W c$VDC  
this.nEndPos = nEnd; UvM4-M%2JN  
nThreadID = id; 3o0ZS^#eB  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 t\ a|Gp W  
} m OE!`fd  
Pf<yLT]  
W/b)OlG"2  
public void run() !dU$1:7  
{ <=D  a  
while(nStartPos < nEndPos && !bStop) 7S^G]g!x  
{ ?L0k|7  
H5&._  
t K/.9qP  
try{ VumM`SH  
URL url = new URL(sURL); X/90S2=P  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8UXRM :Z"  
httpConnection.setRequestProperty("User-Agent","NetFox"); /nuz_y\J  
String sProperty = "bytes="+nStartPos+"-"; rGXUV`5Na  
httpConnection.setRequestProperty("RANGE",sProperty); (x?Tjyzw  
Utility.log(sProperty); eG8 l^[  
:=TIq  
erbk (  
InputStream input = httpConnection.getInputStream(); Cl!(F 6K*  
//logResponseHead(httpConnection); h_+  
H0sTL#/L\  
Dg"szJ-   
byte[] b = new byte[1024]; R dwt4A+  
int nRead; y Vm>Pj6  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) RPte[tq  
{ ?w'86^_z  
nStartPos += fileAccessI.write(b,0,nRead); 5ya^k{`+ZO  
//if(nThreadID == 1) P9f`<o  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J|DZi2o  
} *8m['$oyV  
Ie(.T2K  
&e;Qabwxva  
Utility.log("Thread " + nThreadID + " is over!"); Ox&G  [  
bDownOver = true; a!-J=\>9  
//nPos = fileAccessI.write (b,0,nRead); <F(2D<d{;)  
} 3l41"5Fy&  
catch(Exception e){e.printStackTrace ();} .RJMtmp  
} v=0G&x=/  
} m%apGp'=1  
gGUKB2)  
h9CTcWGt  
//打印回应的头信息 : ?BK A0E  
public void logResponseHead(HttpURLConnection con) qy)~OBY  
{ ~IjID  
for(int i=1;;i++) h=:/9O{H  
{ 7>BfHb  
String header=con.getHeaderFieldKey(i); h]k $K  
if(header!=null) ^bfZd  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); vr'cR2  
Utility.log(header+" : "+con.getHeaderField(header)); L 1!V'Hm{  
else 5TB6QLPEwY  
break; \#t)B J2  
} 0 }od Q#  
} KNd<8{'.  
]VLseF  
?z&%VU"  
public void splitterStop() v[^8_y}A`  
{ kDWEgnXK,v  
bStop = true; z|D*ymz*EY  
} PC<_1!M]  
;-kDJ i  
9g5h~ Ma  
} ?X6}+  
)3:0TFS}}k  
=!^ gQ0~4  
/* bNVeL$'  
**FileAccess.java 9yC22C:  
*//文件访问(定位,写) 9tPRQ M7  
package NetFox; *Z_4bR4Q  
import java.io.*; w"s@q$}]8M  
s{yw1:  
dM^Z,; u  
public class FileAccessI implements Serializable{ -"dt3$ju  
mQ"uG?NE  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 uoI7' :Nv  
RandomAccessFile oSavedFile; U\tx{CsSz  
long nPos; /z*Z+OT2  
]>VG}e~b  
wqF?o  
public FileAccessI() throws IOException % (y{Sca  
{ d9M[]{  
this("",0); ()?83Xj[c  
} K8_v5  
! I0xq"  
P$#:$U @  
public FileAccessI(String sName,long nPos) throws IOException Z%qtAPd  
{ \toU zTT  
oSavedFile = new RandomAccessFile(sName,"rw"); QE\ [ EI2  
this.nPos = nPos; i9DD)Y<  
oSavedFile.seek(nPos); QH9t |l  
} nm,LKS7  
Lr$M k#'B  
/D3{EjUE=  
public synchronized int write(byte[] b,int nStart,int nLen) x1.S+:  
{ r@{TN6U  
int n = -1; 7PX`kI  
try{ {}$7Bp  
oSavedFile.write(b,nStart,nLen); Lz'VQO1U=  
n = nLen; MVsFi]-  
} Nhjq.&  
catch(IOException e) ZP<<cyY  
{ nTEN&8Y>R  
e.printStackTrace (); TQF+aP8[L  
} F^ 75y?  
j ) 6  
IT_I.5*A2  
return n; KkA)p/  
} k||t<&`Ze  
W-=6:y#A  
V*uE83x 1  
} E[]5Od5#  
MYWkEv7  
;=ddv@  
/* "d_wu#fO)  
**SiteInfoBean.java %L+q:naZe  
*/ 5 8bW  
package NetFox; J,2V&WuV0r  
b|d-vnYE  
[>O!~  
public class SiteInfoBean { 50^ux:Uv+N  
o8bdL<  
"?I#!t%'  
private String sSiteURL; //Site's URL ~|V^IJZ22  
private String sFilePath; //Saved File's Path mLX/xM/T?/  
private String sFileName; //Saved File's Name 0@ Y#P|QF  
private int nSplitter; //Count of Splited Downloading File ]%' AZ`8  
A9$x8x*Lt  
Yq+ 1kA  
public SiteInfoBean() Lnr9*dm6q  
{//nSplitter的缺省值为5 NBYJ'nA%;f  
//default value of nSplitter is 5 ]:|B).  
this("","","",5); 6p9fq3~7Y  
} )>iOj50n3  
;o_F<68QP  
cMw<3u\  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) k{}> *pCU  
{ <+roY"  
sSiteURL= sURL; r )F;8(  
sFilePath = sPath; j[G`p^ul  
sFileName = sName; 4b8G 1fm  
this.nSplitter = nSpiltter; s,HbW%s  
utlr|m Xc  
u,sR2&Fe  
} ~||0lj.D  
_%w680b'  
<^5!]8*O  
public String getSSiteURL() z5E%*]  
{ !+GYu;_  
return sSiteURL; mci> MEb  
} *]$B 9zVs!  
7'G;ijx  
M.W X&;>  
public void setSSiteURL(String value) n|(lPbD  
{ nf.Ox.kM)  
sSiteURL = value; )4yP(6|lx  
} H+v&4}f  
k^J8 p#`6  
^q:-ZgM>  
public String getSFilePath() "4N&T#  
{ I |Oco?Q"  
return sFilePath; <LHhs <M'  
} n5:uG'L\  
Qs6<(zaqkt  
c4Ebre-Oa  
public void setSFilePath(String value) 380`>"D  
{ po| Ux`u  
sFilePath = value; F2"fOS  
} E }L Hp  
kpm;ohd  
F-&tSU,  
public String getSFileName() 66yw[,Y  
{ J=g)rd[`  
return sFileName; ,;k+n)  
} 9/ <3mF@E  
TZn 15-O  
F.9}jd{  
public void setSFileName(String value) .wfydu)3  
{ u`pTFy  
sFileName = value; g'"~'  
} Qb536RpcTY  
5ZCu6 A  
Q:}]-lJg  
public int getNSplitter() w#A)B<Y/"  
{ h4Crq Yxa_  
return nSplitter; V6]6KP#D  
} Jw)JV~/0  
J'44j;5&  
-ng1RA>  
public void setNSplitter(int nCount) !/FRL<mp  
{ R\j~X@vI  
nSplitter = nCount; R9XU7_3B  
} +VIA@`4  
} @8d 3  
XT7m3M  
#<{v~sVp&  
/* {6i|"5_j  
**Utility.java ejN/U{)jK'  
*/ zakhJ  
package NetFox; ?qh-#,O9B  
HsY5wC  
9&+]YY CS-  
public class Utility { 7;>|9k  
t7=D$ua  
 a_?sJ  
public Utility() /%@;t@BK4  
{ /jv/qk3i  
\"lz,bT  
Lqgrt]L_"  
} vDjH $ U  
}b_Ob  
//线程睡眠 3>O|i2U  
public static void sleep(int nSecond) o[Iu9.zJpy  
{ %>KbaM1b  
try{ >0^<<=m  
Thread.sleep(nSecond); !~#zd]0x;  
} UU=]lWib  
catch(Exception e) k^5Lv#Z  
{ p9v:T1 ?  
e.printStackTrace (); tv#oEM9esl  
} =uP? ?E  
} U1\7Hcs$  
-Vn#Ab_C  
//日志 b3A0o*  
public static void log(String sMsg) 0|&@)`  
{ Ho &Q }<(  
System.err.println(sMsg); O8]e(i  
} 80lei  
R%UTYRLUn  
 -WC0W  
public static void log(int sMsg) nFnM9 pdMK  
{ +B*]RL[th  
System.err.println(sMsg); 7l* &Fh9;  
} 2` o @L  
} ]$smFF  
" U\RN  
t2[/eM.G  
/* qTJhYxm  
**TestMethod.java jTa\I&s,A  
*/ gN/<g8  
package NetFox; F0$w9p  
y4-kuMYR  
g=Z52y`N<  
public class TestMethod { AC RuDY  
]az(w&vqg2  
'=dQ$fs  
public TestMethod() mnm ZO}   
{ ///xx/weblogic60b2_win.exe Qs1p  
try{ Oe5rRQ$O  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); wf8{v  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4=Th<,<  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2Q6;SF"Z  
fileFetch.start(); K(;qd Ir  
} f,G*e367:  
catch(Exception e){e.printStackTrace ();} =gVMt  
-1Q24jrO-  
8iIp[9~=  
} q`xc h[H  
+ktv : d  
:\^b6"}8  
public static void main(String[] args) f@i#Znkf*?  
{ <K CI@  
new TestMethod(); N@d~gE&^  
} 5,Fq:j)MxW  
} yCQvo(V[F  
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