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http断点续传简单实现(java)

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/* hL3,/^;E,  
**SiteFileFetch.java $3[cBX.=  
*/ =3zn Ta }  
package NetFox; @NH Ruk+  
import java.io.*; '0O[d N  
import java.net.*; eB\r/B]  
"aBd0i&  
H3c=B /+  
public class SiteFileFetch extends Thread { w7Pe< vT  
x@Y2jM  
>=`c [=:Z_  
SiteInfoBean siteInfoBean = null; //文件信息Bean 4bxkp3~h;  
long[] nStartPos; //开始位置  vV[dJ%  
long[] nEndPos; //结束位置 5"gRz9Ta`  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 0%qUTGj  
long nFileLength; //文件长度 (En\odbvt  
boolean bFirst = true; //是否第一次取文件 #VOjnc/rW  
boolean bStop = false; //停止标志 (wlsn6h  
File tmpFile; //文件下载的临时信息 z8j(SI;3  
DataOutputStream output; //输出到文件的输出流 qE`=^  
V- cuG.  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) #pe{:f?  
public SiteFileFetch(SiteInfoBean bean) throws IOException @\D D|o67  
{ Ad,r(0a LZ  
siteInfoBean = bean; hKTg~y^  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); >4ct[fW+  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");  `JE>GZ Y  
if(tmpFile.exists ()) Me}TW!GC  
{ #LN I&5  
bFirst = false; \i,cL)HM  
read_nPos(); -PnC^r0L$  
} HEuM"2{DMM  
else $&C(oh$:  
{  q%k+x)  
nStartPos = new long[bean.getNSplitter()]; )a^Yor)o"  
nEndPos = new long[bean.getNSplitter()]; bSr 'ji  
} 6oP{P_Pxi  
Z M+Hb_6f  
tRy D@}  
ZmULy;{<)  
} `Q&] dE=  
&1p8#i  
+r0eTP=zf  
public void run() 4{DeF@@  
{ bS<@Rd{g  
//获得文件长度 Jrk^J6aa  
//分割文件 qp W#!Vbx  
//实例FileSplitterFetch 2Z O'X9  
//启动FileSplitterFetch线程 [)3 U])w/  
//等待子线程返回 B (1,Rq[  
try{ _onp%*  
if(bFirst) p0rwiBC=q  
{ O8r"M8  
nFileLength = getFileSize(); ^)q2\ YE;  
if(nFileLength == -1) 8`G{1lr4o  
{ 30_un  
System.err.println("File Length is not known!"); MA+-2pMc|7  
} ;-?ZI$  
else if(nFileLength == -2) {}pqxouE  
{ Is@a,k  
System.err.println("File is not access!"); &'7"i~pC  
} ~B&*7Q7  
else pIu H*4Vz  
{ m I zBK]@^  
for(int i=0;i<nStartPos.length;i++) %<?ciU  
{ QklNw6,  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); f%{Tu`  
} ;:c%l.Y2  
for(int i=0;i<nEndPos.length-1;i++) B Z?W>'B%$  
{ aEDN]O95?  
nEndPos = nStartPos[i+1]; O|Ic[XfLx  
} C|f7L>qe  
nEndPos[nEndPos.length-1] = nFileLength; tHtV[We.:  
} /Tj"Fl\h  
} Tdwwtbe  
,%h!%nz!  
R9l7CJM@  
//启动子线程 "F"_G  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >Mn>P!  
for(int i=0;i<nStartPos.length;i++) {1MGb%xW  
{ v{2DBr  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), tin|,jA =  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;a#*|vx  
nStartPos,nEndPos,i); *9vA+uN  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ey)u7-O  
fileSplitterFetch.start(); ZCBPO~&hO'  
} F:J7|<J^F  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^W"Q (sh  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); % kx ^/DH  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !&`\ LJ=j  
nEndPos = " + nFileLength); n`)7Y`hBhP  
// fileSplitterFetch[nPos.length-1].start(); Ao":9r[V  
)M'UASB;8  
~" 0@u  
//等待子线程结束 _~[?> cF%  
//int count = 0; JT|u;Z*n  
//是否结束while循环 ?{: D,{+  
boolean breakWhile = false; GzFE%< 9F  
,<3uc  
Hl3)R*&'J  
while(!bStop) 3u*hT T  
{ UQ3@@:L_  
write_nPos(); kwHqvO!G  
Utility.sleep(500); VkpHzr[k  
breakWhile = true; k\pDJ7wF^  
Mi}I0yhVm  
5_)@B]~nM  
for(int i=0;i<nStartPos.length;i++) 3eTrtCe$  
{ YN@6}B#1  
if(!fileSplitterFetch.bDownOver) NLQE"\#a  
{ %)axGbZG;  
breakWhile = false; OB6J.dF[%  
break; Vf 0fT?/K  
} \C K(;J  
} xHB/]Vd-  
if(breakWhile) GVG!sM mnX  
break; 8PBU~mr  
 *q*HGW5  
nG"n-$A?<  
//count++; !&`}]qQZ  
//if(count>4) "#pzZ)Zh  
// siteStop(); >+ ]R4  
} S= -M3fP~  
V5a?=vK9  
2vc\=  
System.err.println("文件下载结束!"); vUYJf99B  
} A)hhnb0o  
catch(Exception e){e.printStackTrace ();} !7*(!as  
} efjO8J[uk-  
.Z=Ce!  
I1)-,/nEjg  
//获得文件长度 )'5<6Q.]  
public long getFileSize() %X4-a%512  
{ ivzAlwP  
int nFileLength = -1; v**z$5x9  
try{ d(fPECv(  
URL url = new URL(siteInfoBean.getSSiteURL()); gF[6c`-s  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M!gBmQZ1  
httpConnection.setRequestProperty("User-Agent","NetFox"); hr$Sa  
?j/kOD0  
_BV`,`8}  
int responseCode=httpConnection.getResponseCode(); QqtC`H\  
if(responseCode>=400) Hz?!BV0  
{ P8wy*JvT  
processErrorCode(responseCode); ptpW41t}^  
return -2; //-2 represent access is error oYz!O]j;a  
} tAqA^f*{  
x(PKFn  
k6Ihc?HL  
String sHeader; gYatsFyL  
53 @oP  
(*,8KLV_i  
for(int i=1;;i++) )O3jQ_q=  
{ QjA&IZEC  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); b~_B [cf  
//Utility.log(in.readLine()); 4:vTxNs&S  
sHeader=httpConnection.getHeaderFieldKey(i); $!G`D=  
if(sHeader!=null) ] @X{dc  
{ Xb}!0k/{  
if(sHeader.equals("Content-Length")) qy_%~c87  
{ '>3`rsu  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =}JBA>q(  
break; &%^K,Q"  
} k-"<{V  
} ]9jZndgC  
else ^m*3&x8  
break; E4+b-?PB~  
} 6Rcu a<;2P  
} ~TDzq -U)  
catch(IOException e){e.printStackTrace ();} ; XG]Q<S\  
catch(Exception e){e.printStackTrace ();} BhKO_wQ?:J  
L=,OZ9aA  
&1wpGJqm  
Utility.log(nFileLength); rA,CQypo  
Xv0F:1  
K@HQrv<  
return nFileLength; \a\= gn   
} U98_M)-%&  
->\N_|_  
P5xI  
//保存下载信息(文件指针位置) q IM  
private void write_nPos() v ~"Ef_`  
{ k6@b|  
try{ F>N+<Z  
output = new DataOutputStream(new FileOutputStream(tmpFile)); nfX12y_SXL  
output.writeInt(nStartPos.length); 2"@Ft()]  
for(int i=0;i<nStartPos.length;i++) .Gh%p`<  
{ lop uf/U0  
// output.writeLong(nPos); B{p4G`$i1  
output.writeLong(fileSplitterFetch.nStartPos); Fn!SGX~kx$  
output.writeLong(fileSplitterFetch.nEndPos); ibJl;sJ  
} 7JI:=yY!>:  
output.close(); f =o4I2Y[  
} <Nex8fiJ9  
catch(IOException e){e.printStackTrace ();} pI>*u ]x  
catch(Exception e){e.printStackTrace ();} R:A'&;S  
} I!0JG`&  
$jG4pPG  
b3\B8:XFo|  
//读取保存的下载信息(文件指针位置) (/K5!qh  
private void read_nPos() D`Gt  
{ ^agj4$  
try{ =EW3&+Lt  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); vX+.e1m  
int nCount = input.readInt(); 5`~mqqR5  
nStartPos = new long[nCount]; ?E<c[*F05  
nEndPos = new long[nCount]; QH~Jy*\+PX  
for(int i=0;i<nStartPos.length;i++) .+yW%~0  
{ j0FW8!!-g  
nStartPos = input.readLong(); R& #tSL  
nEndPos = input.readLong(); 7^MX l  
} zDDK  
input.close(); P16YS8$  
} BwxnDeG)  
catch(IOException e){e.printStackTrace ();} _A 2Lv]vfV  
catch(Exception e){e.printStackTrace ();} V^n0GJNo  
} JrDHRIkgm  
QU/fT_ORw  
E-fr}R}  
private void processErrorCode(int nErrorCode) QHzgy?  
{ 2n|CD|V$ux  
System.err.println("Error Code : " + nErrorCode); DyfsTx  
} Mra35  
QU T"z'  
O*G1 QX  
//停止文件下载 ]p]UTCo!'  
public void siteStop() Hx %$ X  
{ !>n|c$=;qk  
bStop = true; #Fs|f3-@  
for(int i=0;i<nStartPos.length;i++) "MnSJ 2  
fileSplitterFetch.splitterStop(); YT=eVg53  
g9KTn4  
aMTFW_w  
} ^Kqf ~yS%  
} Au.:OeJm  
//负责部分文件的抓取 eA=WGy@IcN  
**FileSplitterFetch.java YEv Lhh  
*/ #`ls)-`7  
package NetFox; _KN/@(+F  
m`6VKp{YD  
[i7YVwG4  
import java.io.*; qu~X.pW  
import java.net.*; zizk7<?L .  
l Y'N4x7n  
oNM?y:O  
public class FileSplitterFetch extends Thread { }`o? /!X   
p|qyTeg  
;YyXT"6/p  
String sURL; //File URL KX3KM!*  
long nStartPos; //File Snippet Start Position `8:Kp  
long nEndPos; //File Snippet End Position s-rfS7;  
int nThreadID; //Thread's ID =X1?_~}  
boolean bDownOver = false; //Downing is over jL>:>r  
boolean bStop = false; //Stop identical 1] #9  
FileAccessI fileAccessI = null; //File Access interface K |*5Kwi  
G[Tl%w  
cozXb$bBY  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _xrwu;o0}  
{ ,9of(T(~  
this.sURL = sURL; rzeLx Wt  
this.nStartPos = nStart; /ty?<24ko  
this.nEndPos = nEnd; B,vOsa"x6`  
nThreadID = id; :%X Ls,  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 S8vV!xO  
} UE :HMn6  
XOy2lJ/  
w%a8XnW]1  
public void run() ~/-eyxLTm  
{ -rSIBc:$8  
while(nStartPos < nEndPos && !bStop) #0"~G][#  
{ +(?>-3_z  
U BZ9A  
>#(n"RCHf  
try{ g|%L"-%gJ  
URL url = new URL(sURL); C#Bz >2;#  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d]wD[]  
httpConnection.setRequestProperty("User-Agent","NetFox"); PmX2[7  
String sProperty = "bytes="+nStartPos+"-"; sL^yB  
httpConnection.setRequestProperty("RANGE",sProperty); U|@V 74  
Utility.log(sProperty); h7yqk4'Lq  
Ev9 >@~^  
}-DE`c  
InputStream input = httpConnection.getInputStream(); izZ=d5+K  
//logResponseHead(httpConnection); D'_Bz8H!p  
h|;qG)f^  
{i [y9  
byte[] b = new byte[1024]; %.HJK  
int nRead; zsXpA0~3s  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) E JK0  
{ #8h ;Bj  
nStartPos += fileAccessI.write(b,0,nRead); r8/l P}(F  
//if(nThreadID == 1) c EnkU]  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FjFMR 63  
} BR5BJX  
LT@OWH  
x/fX`y|(}*  
Utility.log("Thread " + nThreadID + " is over!"); ;_?MX/w|&  
bDownOver = true; !>$4]FkV  
//nPos = fileAccessI.write (b,0,nRead); {+.r5py  
} |L6&Gf]#5  
catch(Exception e){e.printStackTrace ();} S:bC[}  
} 1Sz A3c  
} :t("L-GPW  
c64v,Hj9  
,'fxIO  
//打印回应的头信息 3=0E!e  
public void logResponseHead(HttpURLConnection con) K^l:MxO-X  
{ Ms^dRe)  
for(int i=1;;i++) mpw~hW0-  
{ 39i9wrP  
String header=con.getHeaderFieldKey(i); ^jE8+h  
if(header!=null) W"q@Qa`Bm  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *OjKc s  
Utility.log(header+" : "+con.getHeaderField(header)); 4Xj4|Rw%  
else GW^,g@%C  
break; Orn0Zpp<z  
} ]T:;Vo  
} 1bnBji  
J^#:qk  
]< l6s  
public void splitterStop() ,m3e?j@;r  
{ PmpNAVE'  
bStop = true; z+{,WHjo  
} iBg3mc@OO  
uQ1@b-e`5  
o{:xp r=(  
} |*5 =_vF  
OhZgcUqQ8  
u+m,b76  
/* :mppv8bh  
**FileAccess.java -Z-f1.Dm5  
*//文件访问(定位,写) )u%je~Vw  
package NetFox; ~&dyRt W4  
import java.io.*; feM6K!fL`  
bUwn}_7b  
?%tMohL  
public class FileAccessI implements Serializable{ 2B0W~x2=  
/phX'xp  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -Apc$0ZsN  
RandomAccessFile oSavedFile; 7cDU2l  
long nPos; op2Of<{h  
F9"w6;hh  
Ex amD">T  
public FileAccessI() throws IOException Uu s.  
{ /^SAC%PD  
this("",0); S[3iA~)Z-  
} XN=67f$Hw  
,_.I\EY[  
}Db[ 4  
public FileAccessI(String sName,long nPos) throws IOException 3g'S\ G@  
{ s8"8y`u  
oSavedFile = new RandomAccessFile(sName,"rw"); {P%9  
this.nPos = nPos; u7%D6W~m0  
oSavedFile.seek(nPos); IY'=DePd  
} z G }?  
f"G-  
CvSIV7zYo  
public synchronized int write(byte[] b,int nStart,int nLen) 8`>h}Q$  
{ 5zJj]A  
int n = -1; ^FmU_Q0  
try{ >eQr<-8  
oSavedFile.write(b,nStart,nLen); ^ |~ml Y@w  
n = nLen; H<hVTc{K  
} !3n)|~r;K  
catch(IOException e) 5@IB39  
{ b \KL;H/  
e.printStackTrace (); }U~6^2 .,  
} ?liK\C2Z<  
lz#GbXn.  
V]OmfPve  
return n; u-D dq~;|  
} hd\gH^wk  
*K!|@h{60  
/n~\\9#3  
} _/8FRkx  
:bV mgLgG  
EF7+ *Q9  
/* {^mNJ  
**SiteInfoBean.java z?/1Kj}xG  
*/ omO S=d!o  
package NetFox; FuG4F  
.;y#  
'FlJpA}  
public class SiteInfoBean { 6=4wp?  
El_wdbbT  
nkxzk$  
private String sSiteURL; //Site's URL Hgeg@RP Q  
private String sFilePath; //Saved File's Path ORGD  
private String sFileName; //Saved File's Name >z;[2 n'  
private int nSplitter; //Count of Splited Downloading File +d+@u)6  
w\54j)rb  
P./V6i<:  
public SiteInfoBean() h5%<+D<  
{//nSplitter的缺省值为5 +;$oJJ  
//default value of nSplitter is 5 O ,rwP  
this("","","",5); +a&p$\  
} /kL $4CA  
5$DHn ]  
q"O.Cbk  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) />¬$>  
{ B]m@:|Q  
sSiteURL= sURL; 4c oJRqf=  
sFilePath = sPath; U~h'*nV&  
sFileName = sName; GoA4f3  
this.nSplitter = nSpiltter; 3G.5724,  
:tIC~GG]_)  
IDkWGh  
} *n]7  
2LrJ>Mi  
~$' \L  
public String getSSiteURL() Fc~'TBf,,`  
{ `U+l?S^$  
return sSiteURL; RZM"~ 0  
} }kw/W#)J  
4h5g'!9-g  
f|^dD`  
public void setSSiteURL(String value) 5MFxo63  
{ ,jXM3?>B  
sSiteURL = value; O^/Maa/D1  
} I1[g&9,  
A7(hw~+@  
u` oq(?|  
public String getSFilePath() Fk(JSiU  
{ ?)bS['^1)  
return sFilePath; |mdi]TL  
} D9`0Dr}/2  
kb[P\cRa  
iA8U Yd3Q  
public void setSFilePath(String value) 0sI1GhVR  
{ KIR'$ 6pn~  
sFilePath = value; M?=;JJ:  
} * ),8PoT  
OB[o2G<0  
66^ycZCH  
public String getSFileName() TKk-;Y=N  
{ qwIa?!8 o  
return sFileName; J=pztASt  
} i)#s.6.D>  
LL|7rS|o  
;7N Z<k  
public void setSFileName(String value) AuR$g7z  
{ d Le-nF  
sFileName = value; .{;Y'Zc14S  
} RI68%ZoL  
sXd8rj:o  
rr#K"SP  
public int getNSplitter()  ;raN  
{ B||;'  
return nSplitter; .VTy[|o   
} K}6dg<  
Cy*|&=>j  
l>Ub!^;  
public void setNSplitter(int nCount) )lJao  
{ (`? y2n)~W  
nSplitter = nCount; E*#]**  
} ?$e9<lsQq)  
} VUI|.76g  
6a;v&5  
nFe%vu8a  
/* %,hV[[@.  
**Utility.java aR,}W\6M  
*/ TYI7<-Mp:[  
package NetFox; !QDQ_  
# O4gg  
 JHf  
public class Utility { )5|I_PXB  
='TE,et@d  
U^qt6$bK  
public Utility() S1/`th  
{ "R8KQj  
Hcc"b0>}{  
%Th>C2\  
} @iEA:?9uX  
4A9{=~nwT  
//线程睡眠 Xn~I=Ml d  
public static void sleep(int nSecond) $.Q$`/dF  
{ zni)<fmju  
try{ Isx#9C  
Thread.sleep(nSecond); 191&_*Xb  
} PQ@L+],C  
catch(Exception e) ORu2V# Z[  
{ -{`@=U  
e.printStackTrace (); |Yq$s U  
} [!%![E  
} BL 3gKx.'  
a,78l@d(  
//日志 Jv.U Q  
public static void log(String sMsg) #z1H8CFL"  
{ )"+(butI&  
System.err.println(sMsg); !?^b[ nC%  
} 2>*%q%81  
e[Abp~@M1  
=TqQbadp  
public static void log(int sMsg) -48vJR*tC  
{ vP+@z-O  
System.err.println(sMsg); n]dL?BJ  
} pH`44KAuM  
} @-OnHE  
KRjV}\}  
4e;QiTj  
/* =}PdH`S  
**TestMethod.java BcD&sQ2F  
*/ #$3yz'"QF  
package NetFox; G<M:Ak+~  
s&GJW@ |  
udeoW-_  
public class TestMethod { i|1^+;  
xG;-bJu  
D/h/Y) Y  
public TestMethod() Jjl`_X$CB  
{ ///xx/weblogic60b2_win.exe )Fb>8<%  
try{ 4[r/}/iGo  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); fr!Pj(Q1  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Py{ <bd  
SiteFileFetch fileFetch = new SiteFileFetch(bean); (MHAJ]Rx  
fileFetch.start(); d6i6hcQE  
} f{0F|w< gf  
catch(Exception e){e.printStackTrace ();} GUQ{r!S  
h=_mNG>R)  
<w\:<5e'  
} #Wu*3&a]yU  
k<+0o))  
S.!UPkWH  
public static void main(String[] args) :$+-3_oLMQ  
{ @ |'5 n  
new TestMethod(); wW>)(&!F  
} w\}?(uO  
} >[6{LAe~hp  
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