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http断点续传简单实现(java)

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/* U#gv ~)\k  
**SiteFileFetch.java tj< 0q<is  
*/ )BX-Y@fpA  
package NetFox; g@s'-8}X^  
import java.io.*; mA" 82"   
import java.net.*; XJ*W7HD  
W^T6^q5;H  
Hphfqdh0`  
public class SiteFileFetch extends Thread { Ks/Uyu. X  
r$/.x6g//  
S!{Kn ;@  
SiteInfoBean siteInfoBean = null; //文件信息Bean tLc~]G*\`s  
long[] nStartPos; //开始位置 jHx)q|2\  
long[] nEndPos; //结束位置 ?S0gazZm  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 y^tp^  
long nFileLength; //文件长度 iTpK:p X  
boolean bFirst = true; //是否第一次取文件 s]@k,%  
boolean bStop = false; //停止标志 <uL0 M`u3  
File tmpFile; //文件下载的临时信息 R)u ${  
DataOutputStream output; //输出到文件的输出流 >=!$(JgX  
bA*T1Db,t>  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) O ]Stf7]%;  
public SiteFileFetch(SiteInfoBean bean) throws IOException O~u@J'4  
{ 'boAv%1_sa  
siteInfoBean = bean; nv-_\M   
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); +jrMvk"  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); m L,El2  
if(tmpFile.exists ()) L\/YS;Y  
{ = k|hH~  
bFirst = false; "PtOe[Xk  
read_nPos(); 9xZ?}S:d  
} (U@uJ  
else S /)J<?<b  
{ *s}j:fJ  
nStartPos = new long[bean.getNSplitter()]; r<XlIi  
nEndPos = new long[bean.getNSplitter()]; I]B[H6  
} 0ofl,mXW  
t^(#~hx  
1Yb9ILX[J  
BdYl sYp  
} > qDHb'  
"YQ%j+  
^{(i;IVG  
public void run() 5^GFN*poig  
{ VQ]MJjvb  
//获得文件长度 B'` jdyaE9  
//分割文件 8C4 =f  
//实例FileSplitterFetch O,A}p:Pgs  
//启动FileSplitterFetch线程 l0g`;BI_  
//等待子线程返回 Da WzQe=  
try{ /c9%|<O%  
if(bFirst) 1WbawiG}  
{ J"W+9sI0  
nFileLength = getFileSize(); J`@#yHL  
if(nFileLength == -1) q oJ4w7  
{ Ze>Pg.k+  
System.err.println("File Length is not known!"); 'RjMwJy{  
} M~ ^ {S[o  
else if(nFileLength == -2) ZPolE_P7  
{ JJn+H&[B  
System.err.println("File is not access!"); }5qjGD  
} r" )zR,  
else 2xJT!lN  
{ ~!G&K`u  
for(int i=0;i<nStartPos.length;i++) $h|rd+},  
{ 8G0DuMI5  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); TR([u  
} JHCV7$RS  
for(int i=0;i<nEndPos.length-1;i++) lS:R##  
{ B>TI dQ  
nEndPos = nStartPos[i+1]; . 7EZB  
} &ivPY  
nEndPos[nEndPos.length-1] = nFileLength; }bxx]rDl  
} `+go| 5N2  
} Q8sCI An{  
%=O$@.%Zc  
Hxm CKW!  
//启动子线程 YvP u%=eF  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; gc6T`O-_;  
for(int i=0;i<nStartPos.length;i++) 0XNj! ^&  
{ T2$V5RyX  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .Iret :  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !agtgS$qII  
nStartPos,nEndPos,i); /\B[lRn  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gUq)M  
fileSplitterFetch.start(); {=Ku9\  
} v8L&F9 o  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +v}R-gNR  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (KDv>@5  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", w'b|*_Q4Q  
nEndPos = " + nFileLength); xp>p#c  
// fileSplitterFetch[nPos.length-1].start(); 95G*i;E  
9ywPWT[^  
.+"SDt oX  
//等待子线程结束 T'TxC)  
//int count = 0; `*1059   
//是否结束while循环 ^9Je8 @Yu  
boolean breakWhile = false; @Fl&@ $  
cKj6tT"=O  
[Bz'c1  
while(!bStop) uPtHCP6  
{ sa71Vh{  
write_nPos(); &2!F:L  
Utility.sleep(500); .7nr:P  
breakWhile = true; &$ ?i  
"w\Iz]  
W]v[Xm$q  
for(int i=0;i<nStartPos.length;i++) Je6=N3)  
{ oV c l (  
if(!fileSplitterFetch.bDownOver) r|WoM39bp  
{ 0*.> >rI  
breakWhile = false; :K) =Hf2y  
break; 9N[vNg<n  
} *<**rY*  
} Z`l97$\  
if(breakWhile) EPz$`#Sh"  
break; /?; 8F  
_S(]/d(c  
5[Ryc[  
//count++; n+EK}= DK  
//if(count>4) oR=^NEJv  
// siteStop(); \c! LC4pE  
} rX%qWhiEJ  
jnK8 [och  
U?6YY` A8  
System.err.println("文件下载结束!"); l_!.yV{  
} 'xdM>y#S  
catch(Exception e){e.printStackTrace ();} "=unDpq]  
} X^#.4:>.  
}[u9vZL  
R0y@#}JH  
//获得文件长度 3mIX9&/  
public long getFileSize() _[SP*" ]H  
{ A}#@(ma7  
int nFileLength = -1; ]]s_ 8u 3  
try{ #EpDIL  
URL url = new URL(siteInfoBean.getSSiteURL()); &Z+a (  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lHpo/ R :  
httpConnection.setRequestProperty("User-Agent","NetFox"); E( M\U5o:  
[FKmZzEy  
% 8kbX  
int responseCode=httpConnection.getResponseCode(); j\nnx8`7  
if(responseCode>=400) 3:a}<^DuCS  
{ aW3yl}`{  
processErrorCode(responseCode); VwoCR q*  
return -2; //-2 represent access is error fV3!x,H  
} AAsl )  
H{x}gBQ  
unmuY^+<  
String sHeader; n>\BPiz  
YtNoYOB  
AQ-P3`bCb  
for(int i=1;;i++) d8g3hyI5\  
{ Q=yQEh|Y  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Dd*T5A?  
//Utility.log(in.readLine()); HPAg1bV:-  
sHeader=httpConnection.getHeaderFieldKey(i); -9{}rE  
if(sHeader!=null) y^zVb\"4  
{ R,A|"Q  
if(sHeader.equals("Content-Length")) p]:~z|.Ba  
{ g~%=[1  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); O'm&S?>  
break; @]d N   
} +*g[hRw[  
} 5.xvOi|.  
else <27B*C M  
break; h^$>{0"  
} IgC)YIhd  
} V0L^pDLOV  
catch(IOException e){e.printStackTrace ();} "8Pxf=   
catch(Exception e){e.printStackTrace ();} `NV =2T  
<P( K,L?r  
LaJc;Jt$  
Utility.log(nFileLength); G`w,$:,  
-nO('(t  
uavts9v<  
return nFileLength; 7(~^6Ql!  
} 96vv85g  
3OFv_<6  
7 .+kcqX  
//保存下载信息(文件指针位置) S'Q$N-Dy  
private void write_nPos() Y_%\kM?7  
{ AY0o0\6cw  
try{ "[H9)aAj7  
output = new DataOutputStream(new FileOutputStream(tmpFile)); sb(,w  
output.writeInt(nStartPos.length); " %|CD"@  
for(int i=0;i<nStartPos.length;i++) {Y'DUt5j  
{ RgQ\Cs24Q  
// output.writeLong(nPos); Yq/|zTe{  
output.writeLong(fileSplitterFetch.nStartPos); QE!cf@~n"  
output.writeLong(fileSplitterFetch.nEndPos); |82V` CV  
} >Q+a'bd w  
output.close(); .Rc&EO  
} [O [ N_z  
catch(IOException e){e.printStackTrace ();} d[rxmEXht  
catch(Exception e){e.printStackTrace ();} lyZof_/*  
} g@nk0lQewj  
+ 7E6U*  
WLNkO^zb  
//读取保存的下载信息(文件指针位置) +zs;>'Sf  
private void read_nPos() <g,k[  
{ O(/K@e  
try{ 1WcT>_$  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); J~<:yBup}  
int nCount = input.readInt(); 4pq>R  
nStartPos = new long[nCount]; ?Dm!;Z+7  
nEndPos = new long[nCount]; H:9( XW  
for(int i=0;i<nStartPos.length;i++) DfV_08  
{ PpU : 4;en  
nStartPos = input.readLong(); 3=dGz^Zdv:  
nEndPos = input.readLong(); MkJL9eG  
} o|alL-  
input.close(); $z@e19gT  
} f*5=,$0  
catch(IOException e){e.printStackTrace ();}  IO>Cyo  
catch(Exception e){e.printStackTrace ();} Fw"~f5O  
} ,[Cl'B  
2HQ'iEu$  
~z|/t^  
private void processErrorCode(int nErrorCode) 3u{[(W}08  
{ f#JLE+0Y  
System.err.println("Error Code : " + nErrorCode); = "c _<?=[  
} iyH<!>a  
rIge6A>I  
sd8o&6  
//停止文件下载 51;(vf  
public void siteStop() do=VPqy  
{ ]X?+]9Fr  
bStop = true; s o~p+]  
for(int i=0;i<nStartPos.length;i++) f^%vIB ~[  
fileSplitterFetch.splitterStop(); %7 J  
"[GIW+ui  
mvUYp,JECl  
} R"O9~s6N  
} M_79\Gz"  
//负责部分文件的抓取 =nid #<X  
**FileSplitterFetch.java %Si3t2W/  
*/ #0xvxg%{  
package NetFox; %$]u6GKabi  
h.2!d0j]  
#llc5i;  
import java.io.*; hH[JY(V  
import java.net.*; LDPo}ogs  
Nob(bD5SpE  
?m?e2{]u,  
public class FileSplitterFetch extends Thread { 'd6hQ4Vw4  
8zVXQ!'  
&]vd7Q.t  
String sURL; //File URL u3k+Xg:  
long nStartPos; //File Snippet Start Position 'a"<uk3DT  
long nEndPos; //File Snippet End Position ZklidHL');  
int nThreadID; //Thread's ID C 7+TnJ  
boolean bDownOver = false; //Downing is over k9R1E/;  
boolean bStop = false; //Stop identical 1Tiq2+hmf  
FileAccessI fileAccessI = null; //File Access interface HHEFX9u  
>Q5 SJZ/  
h Qu9ux  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException kN]#;R6  
{ Xd|5{  
this.sURL = sURL; 3tLh{S?uJ  
this.nStartPos = nStart; mDV 2vg  
this.nEndPos = nEnd; `RmB{qgB  
nThreadID = id; 9wWjl}%  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4-3B"  
} |{oKhC^yG  
dr/!wr'&hS  
{5%<@<? )  
public void run() W8":lpp  
{ 7d4R tdI  
while(nStartPos < nEndPos && !bStop) f "-<Z_  
{ w$B7..r  
IRS^F;)  
v"$; aJ  
try{ -OkKLub  
URL url = new URL(sURL); A>k+ 4|f  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^R<= }  
httpConnection.setRequestProperty("User-Agent","NetFox"); W%h<@@c4,  
String sProperty = "bytes="+nStartPos+"-"; ORHC bw9  
httpConnection.setRequestProperty("RANGE",sProperty); 8g0& (9<)  
Utility.log(sProperty); w[|!$J?  
}%XNB1/`  
'QW 0K]il  
InputStream input = httpConnection.getInputStream(); }y[o[>  
//logResponseHead(httpConnection); {O^1WgGc[  
HQUL?URt  
41C=O@9m  
byte[] b = new byte[1024]; ?xG #4P<C=  
int nRead; /?J_7Lg  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \h0e09& I  
{ A6UtpyS*'  
nStartPos += fileAccessI.write(b,0,nRead); )?TJ{'m  
//if(nThreadID == 1) 7NXT.E~2  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KY"~Ta`  
} -#Wc@\;  
<B``/EX^  
< )?&Jf>_  
Utility.log("Thread " + nThreadID + " is over!"); =8J\;h  
bDownOver = true; hQet?*diU  
//nPos = fileAccessI.write (b,0,nRead); 6Q wL  
} `zsKc 6%  
catch(Exception e){e.printStackTrace ();} ]mqB&{g  
} u>? VD%  
} !*\^-uvaK  
t(_XB|AKm  
"thu@~aC  
//打印回应的头信息 /aPq9B@  
public void logResponseHead(HttpURLConnection con) hi ]+D= S  
{ n1;V2k{uV  
for(int i=1;;i++) YWdlE7 y  
{ (PB|.`_<H  
String header=con.getHeaderFieldKey(i); Aw|3W ]  
if(header!=null) '$U"RP^(  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <Jvr mm[  
Utility.log(header+" : "+con.getHeaderField(header)); j5HOdy2  
else dm 2_Fj  
break; Q,DumOq  
} k~hL8ZT[  
} v~xG*e  
Em?skUnG,  
X:!%"K%}  
public void splitterStop() x)GoxH~#  
{ DV.MvFV  
bStop = true; y1AS^'  
} ^1nf|Xj [  
&#)3v8  
lW2qVR  
} oC?b]tzj  
yqYX<<!V  
RoiMvrJQP  
/* onmO>q*  
**FileAccess.java x Dr^&rC  
*//文件访问(定位,写) Uex b>|  
package NetFox; Y/hay[6  
import java.io.*; Fd 91Y  
<l6CtK@  
>/n/n{{  
public class FileAccessI implements Serializable{ w5|"cD#8A  
lWdE^-  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :kUH>O  
RandomAccessFile oSavedFile; {B}0LJIpL  
long nPos; m|y]j4  
#z~oc^J^T  
5eU/ [F9  
public FileAccessI() throws IOException -y AIrvO1q  
{ &0l Nj@/  
this("",0); f[v??^  
} ~Ch`A@=5  
ULJI` I|m  
\\T I4A^#  
public FileAccessI(String sName,long nPos) throws IOException D"Xm9 (  
{ xv ja  
oSavedFile = new RandomAccessFile(sName,"rw"); -OHG1"/  
this.nPos = nPos; xM*v!J,  
oSavedFile.seek(nPos); '2vlfQ@8a~  
} FJ!>3V;}  
+X&B'  
FD6|>G  
public synchronized int write(byte[] b,int nStart,int nLen) 3! +5MsR+  
{  ;js7rt  
int n = -1; +:t1PV;l  
try{ W,<Vr2J[  
oSavedFile.write(b,nStart,nLen); g5"g,SFGr  
n = nLen; 78Gvc~j  
} m ;KP  
catch(IOException e) EbW7Av  
{ }cP 3i  
e.printStackTrace (); Gq{v)iN  
} w_-{$8|  
qle\c[UM5  
(u*]&yk  
return n; dfrq8n]  
} *7R3EUUk  
S38D cWIw  
!pN,,H6Y  
} @M,_mX  
[W2p}4(  
PaZFM  
/* |9%>R*  
**SiteInfoBean.java A6sBObw;  
*/ kgQEg)A]!x  
package NetFox; 5|Y4GQVz  
!98s[)B:  
Gzs x0%`)  
public class SiteInfoBean { $0 l i"+  
hcBfau;r  
z><JbSE?  
private String sSiteURL; //Site's URL n8iN/Y<%U  
private String sFilePath; //Saved File's Path 9xSAWKr,l  
private String sFileName; //Saved File's Name ="u(o(j"  
private int nSplitter; //Count of Splited Downloading File bH= 5[  
LHa cHv  
,:#prT[P"  
public SiteInfoBean() [Ea5Bn;~!  
{//nSplitter的缺省值为5 :l6sESr  
//default value of nSplitter is 5 ;Y~;G7  
this("","","",5); ~MXPiZG?  
} [<%yUy  
G,XFS8{%  
:hevBBP  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b\^.5SEw  
{ >g F  
sSiteURL= sURL; IUZsLNW  
sFilePath = sPath; q<7Nz] Td  
sFileName = sName; iWvgCm4  
this.nSplitter = nSpiltter; P_qxw-s  
`R; ct4-  
o30PI  
} bFTWuM  
51rM6 BT  
B0YY7od  
public String getSSiteURL() ]=pEs6%O3  
{ r%o!P`  
return sSiteURL; #<?j784  
}  @P~ u k  
ir\   
7tyn?t0n  
public void setSSiteURL(String value) KcSvf;sx  
{ ly{ ~X  
sSiteURL = value; 5[@4($q8  
} q_W NN/w  
ha(hG3C  
Ya>cGaLq  
public String getSFilePath() )JZfC&,  
{ ZkK +?:9  
return sFilePath; >`lf1x  
} M r@M~ -  
8HWY]:| oh  
1&m08dZm5  
public void setSFilePath(String value) ^beW*O!  
{ myXp]=Sb?  
sFilePath = value; D9Q%*DLd$_  
} ]r#tJ T`M  
{UwJg  
"7gHn0e>  
public String getSFileName() 9,F(f}(t  
{ M,<%j  
return sFileName; =si<OB  
} 8Y4YE(x5  
z?cRsqf  
!Dun<\  
public void setSFileName(String value) AA@J~qd u  
{ 3<Cd >o.  
sFileName = value; 578Dl(I#)  
} t<$yxD/R  
)ll}hGS  
=JEnK_@?K\  
public int getNSplitter() &yYK%~}t[  
{ AJq'~fC;I  
return nSplitter; (3 _2h4O  
} esxU44  
o fN|%g /  
*%g*Np_P  
public void setNSplitter(int nCount) <FGM/e4  
{ gBrIqM i5  
nSplitter = nCount; vL-%"*>v  
} B_:K.]DK`  
} cDLS)  
& 8e~<  
Prr<:q  
/* R` /n sou  
**Utility.java KaO8rwzDN  
*/ ncu> @K$n  
package NetFox; Z\NC+{7k]  
/X8b=:h  
Mc{1Cdj  
public class Utility { Vrz<DB^-e  
qxE~Moht  
0PTB3-  
public Utility() 9t;aJFI  
{ 3A'd7FJ0G  
b7HS 3NYk  
I_N"mnn@Nr  
} m3.d!~U\  
9;q@;)'5  
//线程睡眠 pNE!waR>  
public static void sleep(int nSecond) ]%G[<zD,1  
{ /&dC?bY  
try{ T w/CJg  
Thread.sleep(nSecond); U<o,`y[Tn  
} Qx$Yj  
catch(Exception e) Jw9|I)H  
{ DUY#RJf  
e.printStackTrace (); < R0c=BZ>  
} <L:v28c  
} \@gs8K#  
#y2="$ V  
//日志 MNkysB(  
public static void log(String sMsg) `}Q+:  
{ W0l|E&fj[  
System.err.println(sMsg); aS:17+!  
} `W{Ye=|[d#  
qH"e: wgL  
@;Yb6&I;  
public static void log(int sMsg) |jc87(x <  
{  03_tt7  
System.err.println(sMsg); a\^DthZ!;|  
} #^#N%_8  
} =suj3.   
aRg- rz  
RIb< 7  
/* N2=gSEY  
**TestMethod.java .2Gn)dZU  
*/ fs7JA=?:  
package NetFox; >:h 8T]F  
:^! wQ""  
kLADd"C  
public class TestMethod { e-\J!E'1F  
CKrh14ul  
2"JIlS;J}7  
public TestMethod() v"=^?5B  
{ ///xx/weblogic60b2_win.exe (9@6M 8A  
try{ f4]nz:2  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]D%D:>9|/  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); NCl$vc;,  
SiteFileFetch fileFetch = new SiteFileFetch(bean); R&=Y7MfZ  
fileFetch.start(); qvhTc6oH  
} `{8Sr)  
catch(Exception e){e.printStackTrace ();} e,|"9OK  
NuW9.6$Jrf  
?Tt/,Hl?D  
} yz,ak+wp  
{_KuztJGA  
4?1Ac7bE  
public static void main(String[] args) !Kd/ lDY  
{ {#0B~Zr  
new TestMethod(); bG;vl; C  
} JKGUg3\~  
} Z9 }qds6 y  
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