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http断点续传简单实现(java)

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/* @)>D))+  
**SiteFileFetch.java zf.- I  
*/ H{?9CxYa  
package NetFox; j}F-Xs+  
import java.io.*; xq %{}  
import java.net.*; BR v+.(S  
)i>[M"7  
&3v&i*DG,I  
public class SiteFileFetch extends Thread { =H %-.m'f2  
FG%j {_Ez  
2oZ9laJO  
SiteInfoBean siteInfoBean = null; //文件信息Bean ^ *&X~8@)  
long[] nStartPos; //开始位置 :s-o0$PlJ  
long[] nEndPos; //结束位置 EQIUSh)M  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 `p0ypi3hn  
long nFileLength; //文件长度 2$ !D* <  
boolean bFirst = true; //是否第一次取文件 wNNB;n` l  
boolean bStop = false; //停止标志 2b=)6H1  
File tmpFile; //文件下载的临时信息 B51kV0  
DataOutputStream output; //输出到文件的输出流 U{~SXk'2+  
/ahNnCtu?1  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ,&7Wa-vf  
public SiteFileFetch(SiteInfoBean bean) throws IOException G\/"}B:(  
{ mmEp'E  
siteInfoBean = bean; 1/ZR*f a  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ]DvO:tM  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); |2`"1gt  
if(tmpFile.exists ()) 4KI [D{  
{ sM\lO  
bFirst = false; dQgk.k  
read_nPos(); Ogg#jx(4  
} .mL#6P!d3^  
else U@Tj B  
{ I\Glc=T*  
nStartPos = new long[bean.getNSplitter()]; ?0<w  
nEndPos = new long[bean.getNSplitter()]; 8BXqZVm.  
} ogeL[7  
h?UVDzI!O  
 T7$S_  
V5D2\n3A  
} V% CUMH =U  
!&] z*t  
Rt(J/%;  
public void run() *Q}[ ]g  
{ (LJ@S eM;  
//获得文件长度 E-ZRG!)[v  
//分割文件 #\4 b:dv  
//实例FileSplitterFetch fT Y/4(  
//启动FileSplitterFetch线程 $R^AEa7  
//等待子线程返回 {hqAnZ@]vr  
try{ !:fv>FEI9  
if(bFirst) ,smF^l   
{ Psa@@'w  
nFileLength = getFileSize(); znZ7*S >6\  
if(nFileLength == -1) ~# 7wdP  
{ beZ(o?uK  
System.err.println("File Length is not known!"); UQd6/mD`e  
} noNm^hFL  
else if(nFileLength == -2) q]<xMg#nu  
{ , fb( WY  
System.err.println("File is not access!"); N dR ]  
} %85Icg  
else W7UtA.2LT  
{ L>Jd7; =  
for(int i=0;i<nStartPos.length;i++) rOl6lQW  
{ u/AT-e r;  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); |V`S >m%N  
} SFjU0*B$  
for(int i=0;i<nEndPos.length-1;i++) =^h~!ovj:  
{ <%bw/  
nEndPos = nStartPos[i+1]; _zC (J  
} 3@5p"X  
nEndPos[nEndPos.length-1] = nFileLength; j%&  IL0  
} V`fL%du,3  
} &K:' #[3V  
#iis/6"  
fk5XvL  
//启动子线程 A%ywj'|z  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *,#q'!Hq  
for(int i=0;i<nStartPos.length;i++) S2=%x.  
{ 0^_MN~s(X  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3;$bS<>  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), PDw{R]V+  
nStartPos,nEndPos,i); BSXdvI1y  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +lp{#1q0  
fileSplitterFetch.start(); ~v: #zU  
} ValS8V*N1  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(),  pbB2wt  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \~"#ld(x7  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", : d'65KMi  
nEndPos = " + nFileLength); [}""@?  
// fileSplitterFetch[nPos.length-1].start(); ,5-Zb3\  
}. %s xw  
;;LuU<,$  
//等待子线程结束 B.-A $/  
//int count = 0; 2mJ:c  
//是否结束while循环 c%<2z  
boolean breakWhile = false; IUhp;iH  
/)1v9<vM"  
]XrE  
while(!bStop) 6$B'Q30}r  
{ Uu2N9.5  
write_nPos(); ha'qIT 3&  
Utility.sleep(500); 2uu[52H8d%  
breakWhile = true; kfpm=dKL  
%yw=[]Vjze  
^!@*P,'I  
for(int i=0;i<nStartPos.length;i++) ]Ti$ztJ  
{ sX'U|)/pD  
if(!fileSplitterFetch.bDownOver) 1*R_"#  
{ \j:gr>4  
breakWhile = false; E\e]K !  
break; d)*(KhYie@  
} _'*DT=H'U  
} wr@GN8e`  
if(breakWhile) u 2lX d'  
break; +#v4B?NR  
7t4v~'h;5e  
Z% Z"VoxH  
//count++; ggCr-  
//if(count>4) *98Ti|  
// siteStop(); di_gWE  
} RV]a%mVlM  
]I XAucI]  
&|,s{?z2  
System.err.println("文件下载结束!"); %<S7  
} 5`UJouHi  
catch(Exception e){e.printStackTrace ();} ;qVG \wQq  
} T5{T[YdX<  
R"Y?iZed3  
jlRS:$|R0  
//获得文件长度 ||gEs/6-  
public long getFileSize() vU9~[I`^p  
{ }wkaQQh  
int nFileLength = -1; -,@bA @&  
try{ (1y='L2rj  
URL url = new URL(siteInfoBean.getSSiteURL()); p5qx=p~c  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z[FI2jl  
httpConnection.setRequestProperty("User-Agent","NetFox"); 9 d] tjT  
T+BIy|O  
ris;Iu^v0  
int responseCode=httpConnection.getResponseCode(); xc *!W*04  
if(responseCode>=400) u S(@?m$  
{ b.6ZfB,+G  
processErrorCode(responseCode); T:@7 S  
return -2; //-2 represent access is error Bb_}YU2#  
} hOSf'mi  
5)x6Q|-u  
8v$ g  
String sHeader; X o_] v  
;:^ Lv  
1bDJ}M~]z  
for(int i=1;;i++) 6#?NL ]A  
{ !Pe1o-O  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Ix4jof6(  
//Utility.log(in.readLine()); sVlZNj9i"  
sHeader=httpConnection.getHeaderFieldKey(i); ) 1BiEK`v  
if(sHeader!=null) As p8qHS  
{ J{^n=X9M0J  
if(sHeader.equals("Content-Length")) /\TlO.B=  
{ rN'.&;Y5  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7zi"caY  
break; |Pj9ZG#  
} ]#M/$?!]g2  
} |#:=\gugh  
else B{N=0 cSi  
break; ha ik  
} w+3>DEfz  
} ^VC7C~NZ!M  
catch(IOException e){e.printStackTrace ();} Flne=ij6g  
catch(Exception e){e.printStackTrace ();} uJm#{[  
1uY3[Z9S  
,?;sT`Mh)  
Utility.log(nFileLength); 6HB]T)n  
A@\qoS[  
,Os7T 1>  
return nFileLength; 9DY|Sa]#=  
} 0\ZaMu #  
wFn@\3%l`  
^$8Vh =D  
//保存下载信息(文件指针位置) `Q+i-y  
private void write_nPos() >9(7h&[Y  
{  =05iW  
try{ KWtu,~O_u  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Sn+FV+D  
output.writeInt(nStartPos.length); u% r!?-z  
for(int i=0;i<nStartPos.length;i++) f>?^uSpWH  
{ L F8Pb;I  
// output.writeLong(nPos); .O;!W<Ef$  
output.writeLong(fileSplitterFetch.nStartPos); X!2.IsIS8  
output.writeLong(fileSplitterFetch.nEndPos); Q Id"Cl)3  
} li1v 4  
output.close(); e2q pJ4i  
} .<0=a|IAz  
catch(IOException e){e.printStackTrace ();} d"LoK,p#  
catch(Exception e){e.printStackTrace ();} tru;;.lj8K  
} DXt]b,  
o- cj&Cv%  
[}jj<!9A_;  
//读取保存的下载信息(文件指针位置) @'@s*9Nr  
private void read_nPos() 3^j~~ "2,w  
{ 3"f)*w7d  
try{ V^9$t/c &  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 'MSEki67  
int nCount = input.readInt(); ze*&*csO  
nStartPos = new long[nCount]; RCoeJ|  
nEndPos = new long[nCount]; d?Ia#K9 3G  
for(int i=0;i<nStartPos.length;i++) s+(l7xH$  
{ %_]=i@Y~  
nStartPos = input.readLong(); 0zlM.rjEZ  
nEndPos = input.readLong(); r.Y*{!t  
} e~tr^$/(  
input.close(); iLjuE)6-$  
} xI-=t ib  
catch(IOException e){e.printStackTrace ();} )PsN_ 42~  
catch(Exception e){e.printStackTrace ();} XKpL4]{&q4  
} u-8X$aJ  
"sz.v<F0:s  
ZTN:|IKT  
private void processErrorCode(int nErrorCode) W\nHX I  
{ lNq:JVJ#\r  
System.err.println("Error Code : " + nErrorCode); 16a_GwfM  
} E \ K  
" whO}  
Wg}B@:`T  
//停止文件下载 RPz!UMQSD  
public void siteStop() ;"d?_{>7  
{ oV%( 37W9=  
bStop = true; =)mXCA^  
for(int i=0;i<nStartPos.length;i++) ?Ry%c6(}  
fileSplitterFetch.splitterStop(); ?ZSXoy-kr  
</K%i;l  
6ctHL<^  
} a7XXhsZ  
} Xtu:  
//负责部分文件的抓取 /%N31   
**FileSplitterFetch.java ws*~$x?7  
*/ Z/XM `Cy  
package NetFox; (#f m (@T  
r78u=r  
H1aV}KD  
import java.io.*; ?Zc/upd:$N  
import java.net.*; >reaIBT  
d~togTs1  
yYxeNE"  
public class FileSplitterFetch extends Thread { *" |VNnB  
FYx `o\  
~zXG<}n  
String sURL; //File URL W+F<P@[u<$  
long nStartPos; //File Snippet Start Position &cv@Kihq(  
long nEndPos; //File Snippet End Position 8`L#1ybMO  
int nThreadID; //Thread's ID )OW(T^>_'I  
boolean bDownOver = false; //Downing is over C8bGae(  
boolean bStop = false; //Stop identical u7<qaOzs?  
FileAccessI fileAccessI = null; //File Access interface Sleu#]-  
*G2)@0 {  
iylBK!ou  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException kT Z?+hx  
{ Lo$Z>u4(c  
this.sURL = sURL; 3*X, {%  
this.nStartPos = nStart; fg>B  
this.nEndPos = nEnd; STFQ";z$  
nThreadID = id; 2A@Y&g(6T7  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 FqT,4SIR  
} =Do3#Xe2V  
l0:e=q2Ax  
EPE!V>  
public void run() j#Ky0+@V  
{ z*NC?\  
while(nStartPos < nEndPos && !bStop) #Lhj0M;a  
{ hJC p0F9O  
Ef,7zKG  
q 2_N90u  
try{ uFm(R/V  
URL url = new URL(sURL); QoT3;<r}  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Tdk2436=  
httpConnection.setRequestProperty("User-Agent","NetFox"); uI[-P}bSc&  
String sProperty = "bytes="+nStartPos+"-"; }rj C_q  
httpConnection.setRequestProperty("RANGE",sProperty); ^hl]s?"3  
Utility.log(sProperty);  &*>C PO  
dIBKE0`  
cKi^C  
InputStream input = httpConnection.getInputStream(); *D09P%  
//logResponseHead(httpConnection); #TW>'l F  
<y\ Z#z  
Y?&DEKFbD  
byte[] b = new byte[1024]; +s/N@]5nW  
int nRead; sw=JUfAhy  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) qmue!Fv#g  
{ ]@ Sc}  
nStartPos += fileAccessI.write(b,0,nRead); 90y9~.v  
//if(nThreadID == 1) M0Kh>u  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7q2"b?|h  
} 8f{}ce'E*  
tz0Ttu=xH  
n ]6 0  
Utility.log("Thread " + nThreadID + " is over!"); aCYm$6LmA  
bDownOver = true; w ~L\Ebg  
//nPos = fileAccessI.write (b,0,nRead); JK:mQ_  
} >XXMIz:  
catch(Exception e){e.printStackTrace ();} qj3bt_F!x  
} lEYT{  
} ~J. Fl[  
Vk N[=0a,  
  Tk v  
//打印回应的头信息 }{kTh%^  
public void logResponseHead(HttpURLConnection con) aG8D%i0  
{ q563,s  
for(int i=1;;i++) &JXHDpd$a^  
{ U>plv  
String header=con.getHeaderFieldKey(i); xvx\H'  
if(header!=null) eMm~7\ R  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Rbj+P;t&  
Utility.log(header+" : "+con.getHeaderField(header)); Kt4\&l-De  
else z:i X]df  
break; AHMV@o`V  
} fN"oa>X  
} -'H+lrmv  
Br ^rK}|l  
!OZh fMVd  
public void splitterStop() *a4b`HRT  
{ ?N!j.E4=  
bStop = true; }N#>q.M  
} ~0^,L3M  
LA=>g/+i.X  
|IcxegE  
} {Y* ]Qc  
"{ QHWZ  
l5y#i7q  
/* _#YHc[Wz  
**FileAccess.java q5\LdI2  
*//文件访问(定位,写) yu?s5  
package NetFox; "<.  
import java.io.*; ?_Dnfa_  
\'LCC-  
7 NB"oU^h%  
public class FileAccessI implements Serializable{ H;t8(-F@'  
't]EkH]BC  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 iq^L~RW5e  
RandomAccessFile oSavedFile; !^w\$cw&  
long nPos; 18/@:u{  
M(h H#_ $  
SJ[@fUxO)  
public FileAccessI() throws IOException \(>$mtS:  
{ Kf?{GNE7  
this("",0); F;Xq:e8  
} xXU/m|  
kN9sug^  
WGG) mh&-  
public FileAccessI(String sName,long nPos) throws IOException mQA<t)1  
{ klC^xSx  
oSavedFile = new RandomAccessFile(sName,"rw"); h%w\O Z7  
this.nPos = nPos; '3u]-GU2_  
oSavedFile.seek(nPos); 1uge>o&  
} UWWD8~:  
rLw[y$2  
dzv,)X  
public synchronized int write(byte[] b,int nStart,int nLen) ~"r wP=<}  
{  ISnS;  
int n = -1; x&fCe{5  
try{ sBXk$  
oSavedFile.write(b,nStart,nLen); ~Ro:mH: w  
n = nLen; UH^wyK bM  
} wIR[2&b  
catch(IOException e) uF3p1by  
{ HToN+z%w3H  
e.printStackTrace (); zkMO3w>  
} qp_ `Fj:  
POg0=32  
5 EuJ  
return n; 8Y0<lfG  
} IV)W|/.  
5Kw?SRFH/  
OO wA{]gK  
} m',_k Y3  
'=b&)HbeK  
hYZ:" x  
/* :kx#];2i  
**SiteInfoBean.java bSmaE7  
*/ }NBJ T4R  
package NetFox; Jx9%8Ek  
vzm4  
E|4XQ|B@  
public class SiteInfoBean { hic$13KuP  
^%X\ }><  
8(f0|@x^  
private String sSiteURL; //Site's URL e/Oj T  
private String sFilePath; //Saved File's Path kt3#_d^El  
private String sFileName; //Saved File's Name <$ZT]pT  
private int nSplitter; //Count of Splited Downloading File G~tOCp="p  
i|,A1c"*  
_>m*`:Wb  
public SiteInfoBean() T\s#-f[x  
{//nSplitter的缺省值为5  ;yER V  
//default value of nSplitter is 5 geN%rD  
this("","","",5); jp]geV54  
} pbvEIa-Y4  
5)v^ cR?&  
K':pU1  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) xAz4ZXj=q  
{ Jo(}#_y?  
sSiteURL= sURL; l(#Y8  
sFilePath = sPath; %y\7  
sFileName = sName; }qdJ8K  
this.nSplitter = nSpiltter; LXF%~^^@d  
j6HbJ#]  
2y7q x1$C  
} 446hrzW>@  
8=o(nFJw  
+2 o|#`)i  
public String getSSiteURL() h>%JG'DV  
{ # %y{mn  
return sSiteURL; x,c68Q)g  
} `6sQlCOnF  
%R"/`N9R,  
}3_G|  
public void setSSiteURL(String value) <T/L.>p4  
{ Kcdd=2 [T  
sSiteURL = value; S^VV^O5 ^  
} a[cH@7W.#  
E=*Q\3G~  
wEc5{ b5M  
public String getSFilePath() 7CMgvH)O  
{ cH-Zj  
return sFilePath; n4&j<zAV{  
} ']Xx#U N  
(g:W|hS  
9S1V! Jp  
public void setSFilePath(String value) 64>[pZF8  
{ w&cyGd D5  
sFilePath = value; uBkn y;  
} xa0%;nFKe  
TXl9c 6  
c]R![sa  
public String getSFileName() 3&Rqz9W  
{ B[|/wHMsT}  
return sFileName; $K fk=@  
} !jq6cND  
76r s)J[*w  
F_ Cz  
public void setSFileName(String value) _-\{kJ  
{ &LQab>{*K  
sFileName = value; T2;  9  
} q.F1Jj  
B "zg85 e  
3 v$4LY  
public int getNSplitter() #7T={mh  
{ hD"~ ^  
return nSplitter; h5keYBA  
} 9d}nyJ  
[te7 uZv-  
'="){  
public void setNSplitter(int nCount) @}!$NI8  
{ w>Sz^_ h  
nSplitter = nCount; ( +hI   
} 8N_rJ)f  
} cGp 6yf  
"a{f? .X.  
v>!}cB/6  
/* ClZyQ=UAD  
**Utility.java ppP?1Il`kb  
*/ "TJ^Z!  
package NetFox; @il}0  
6l7a9IJ  
bLF0MVLM  
public class Utility { v[3sg2.  
^v|!(h\ZC  
DP]|}8~L  
public Utility() 1&"1pH  
{ 0^Cx`xdX:  
S c Kfr  
C8q-gP[  
} :+!b8[?Z  
;rL$z;}8  
//线程睡眠 L-$g& -  
public static void sleep(int nSecond) LXV6Ew5E  
{ =ApT#*D)o  
try{ *60)Vo.=  
Thread.sleep(nSecond);  y-#tU>P  
} gNQJ:!  
catch(Exception e) }!Lr!eALr  
{ !{ lb#  
e.printStackTrace (); d6&tz!f  
} ksp':2d}  
} 9 <m j@bI$  
GqxK|G1  
//日志 b;l%1x9r  
public static void log(String sMsg) 1*jm9])#  
{ iL1so+di  
System.err.println(sMsg); ,[#f}|s_  
} s%|J(0  
`BD`pa7.%  
7S Zs/wWh%  
public static void log(int sMsg) z\ pT+9&  
{ Y%@'a~  
System.err.println(sMsg); \YS\* 'F  
} @CDRbXoFk  
} #JucOWxjY  
=^vUb  
@7'gr>_E  
/* B=|sLs`I  
**TestMethod.java 'WCTjTob/  
*/ GXVGU-br  
package NetFox; >.4Sx~VH2  
kzXW<V9  
R FiR)G ,  
public class TestMethod { |-D.  
0fU>L^P_?  
blv6  
public TestMethod() f}eVfAf  
{ ///xx/weblogic60b2_win.exe 5GkM7Zu!{j  
try{ kGP?Jx\PkH  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); d*HAKXd&:j  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); JH#+E04#  
SiteFileFetch fileFetch = new SiteFileFetch(bean); kw'D2692  
fileFetch.start(); B,T.bgp\  
} `^vD4qD|  
catch(Exception e){e.printStackTrace ();} :Ej)A fS  
m=V2xoMw6  
[y>.)BU  
} Cj9Tj'0@I+  
&KWh5S@w  
th,qq  
public static void main(String[] args) ^5}3FvW  
{ =`H( `2  
new TestMethod(); jN0v<_PJED  
} I|H mbTXa  
} i,T{SV  
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