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http断点续传简单实现(java)

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/* epk C '  
**SiteFileFetch.java T[},6I|!  
*/ C&d,|e "\  
package NetFox; O&.gc p!  
import java.io.*; C\C*@9=&x  
import java.net.*; 0\ j)!b  
QB* AQ5-  
?5d[BV   
public class SiteFileFetch extends Thread { o~:({  
ezJ^ r,D|  
9ys[xOh WM  
SiteInfoBean siteInfoBean = null; //文件信息Bean 2U+wiE|  
long[] nStartPos; //开始位置 /WAOpf5  
long[] nEndPos; //结束位置 yq[CA`zVN  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 "[L+LPET  
long nFileLength; //文件长度 I%{D5.du  
boolean bFirst = true; //是否第一次取文件 i"!j:YEo  
boolean bStop = false; //停止标志 ,`ehR6b  
File tmpFile; //文件下载的临时信息 S^e e<%-  
DataOutputStream output; //输出到文件的输出流 A:sP%c;  
a! x?Apww  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) rJd-e96  
public SiteFileFetch(SiteInfoBean bean) throws IOException >?X(, c  
{ ~|wh/]{b9  
siteInfoBean = bean; ''EFh&F  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ;2eZa|M*q  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); >Cr'dKZ}  
if(tmpFile.exists ()) a=^>A1=  
{ <^A1.o< GN  
bFirst = false; 5=_))v<Tp  
read_nPos(); ~ln96*)M;  
} @F5QgO J&r  
else 0 s%{m<  
{ 7LW %:0  
nStartPos = new long[bean.getNSplitter()]; _vE[TFy  
nEndPos = new long[bean.getNSplitter()]; SC0_ h(zb,  
} V@ph.)z  
24_/JDz  
z6Yx )qBE<  
xOpCybmc  
}  A,|lDsvM  
+Xr87x;  
L)Ru]X`  
public void run() mt3j$r{_  
{ Rwz (20n\^  
//获得文件长度 .[:*bo3  
//分割文件 }%eXGdC  
//实例FileSplitterFetch ulnlRx  
//启动FileSplitterFetch线程 1|\/2  
//等待子线程返回 \>XkK<ye  
try{ J{5&L &4  
if(bFirst) lMBXD?,,J  
{ Kkds^v6  
nFileLength = getFileSize(); k39;7J  
if(nFileLength == -1) 7q _.@J  
{ ::rKW *?  
System.err.println("File Length is not known!"); $5/lU }To  
} &ffd#2f`@  
else if(nFileLength == -2) "*aL(R  
{ ZiOL7#QWX  
System.err.println("File is not access!"); |;_uN q9  
} 4ky@rcD1  
else pO_L,~<  
{ H-.8{8  
for(int i=0;i<nStartPos.length;i++) ~<#!yRy>r  
{ 5}t}Wc8  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); /"<o""<]  
} ${F] N }  
for(int i=0;i<nEndPos.length-1;i++) \.<V~d?  
{ ]1 OZY@  
nEndPos = nStartPos[i+1]; Xm2p<Xu8h  
} AR-&c 3o  
nEndPos[nEndPos.length-1] = nFileLength; Q7$K,7flf;  
} 7R=cxD&  
} ?R}a,k  
eD481r  
_*O^|QbM  
//启动子线程 g0D(:_QXp:  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; zLxO\R!d  
for(int i=0;i<nStartPos.length;i++) @dzO{)  
{ RMx$]wn_  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !5P\5WF~Y  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (ft8,^=4  
nStartPos,nEndPos,i); p=65L  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gz?]]-H  
fileSplitterFetch.start(); 6:(*u{  
} Q~A25Jf .  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(),  Wb/q&o  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <QyJJQM  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &K_"5.7-56  
nEndPos = " + nFileLength); c.u$NnDU6  
// fileSplitterFetch[nPos.length-1].start(); ^$7Lmd.qI  
XJ|CC.]1u  
0P<bS?e<l  
//等待子线程结束 /^kZ}}9baU  
//int count = 0; L`$MOdF{_  
//是否结束while循环 e.<$G'  
boolean breakWhile = false; h$Z_r($b  
]e'Ol$3U9=  
5m`@ 4%)zp  
while(!bStop) yu'2  
{ a+TlZE>8  
write_nPos(); 3JiJ,<,7  
Utility.sleep(500); 9nFPGIz+  
breakWhile = true; J2BW>T!tuw  
meHAa`  
o!`.LL%  
for(int i=0;i<nStartPos.length;i++) (=d%Bn$6b  
{ 5 JE8/CbH  
if(!fileSplitterFetch.bDownOver) L {6y]t7^  
{ $q]:m+Fm  
breakWhile = false; >;N0( xB  
break; ;~Ke5os=s  
} (%huWW j  
} d~](S<k  
if(breakWhile) 7-"ml\z  
break; )&"l3*x  
:*aBiX"  
@;iW)a_M  
//count++; ]VifDFL}  
//if(count>4) ^mLZT*   
// siteStop(); t{\FV@R  
} Iz/o|o]#  
VjbRjn5LI  
X6jW mo8]  
System.err.println("文件下载结束!"); lHBk&UN'  
} #>+O=YO  
catch(Exception e){e.printStackTrace ();} q<L>r?T[  
} :yN;_bC!b%  
\$Xo5f<  
$=7[.z&  
//获得文件长度 &>UI{  
public long getFileSize() acgtXfHR  
{ c <8s \2  
int nFileLength = -1; &?m|PK)I  
try{ _T6l*D  
URL url = new URL(siteInfoBean.getSSiteURL()); 6/ir("LK  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d'~ kf#  
httpConnection.setRequestProperty("User-Agent","NetFox"); pp$WM\r  
byl#8=?  
XK[cbVu  
int responseCode=httpConnection.getResponseCode(); \2(Uqf#_  
if(responseCode>=400) L~_3BX  
{ *NdSL  
processErrorCode(responseCode); V)M+dhl  
return -2; //-2 represent access is error E 5D5  
} 413,O~^  
~1&%,$fZ  
!|hxr#q=4  
String sHeader; iR;Sd >)  
<aJdm!6  
b/IT8Cm3  
for(int i=1;;i++) SoZ$1$o2  
{ t sdkpt  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); uK6`3lCD  
//Utility.log(in.readLine()); BdcTKC  
sHeader=httpConnection.getHeaderFieldKey(i); QXZjsa_|  
if(sHeader!=null) ?N2/;u>  
{ 4fPbwiK j  
if(sHeader.equals("Content-Length")) 1&A@Zo5|  
{ T 9Jv  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +L_!$"I  
break; '\qd{mM\r  
} &z[39Q{~  
} =Nn&$h l  
else bF:]MB^VK  
break; #L[-WC]1y  
} o@TxDG  
} M`!\$D  
catch(IOException e){e.printStackTrace ();} g_?:G$1H  
catch(Exception e){e.printStackTrace ();} p!^.;c  
40cgsRa|  
<Z%iP{  
Utility.log(nFileLength); ]Igd<  
\a]JH\T)Q  
J [}8&sn  
return nFileLength; "Ka2jw,  
} xBH`=e <  
6x%uWZa'  
:#8#tLv  
//保存下载信息(文件指针位置) ({=: N  
private void write_nPos() [ iE%P^  
{ ^c?2n  
try{ D<9FSxl6  
output = new DataOutputStream(new FileOutputStream(tmpFile)); X;JptF^  
output.writeInt(nStartPos.length); W =YFe<Q  
for(int i=0;i<nStartPos.length;i++) S;DqM;Q  
{ jbx@ty  
// output.writeLong(nPos);  # Vz9j  
output.writeLong(fileSplitterFetch.nStartPos); M&P?/Zi=L  
output.writeLong(fileSplitterFetch.nEndPos); @QiuCB  
} vt0XCUnK  
output.close(); +*"u(7AV  
} >r+Dl\R  
catch(IOException e){e.printStackTrace ();} g.-{=kZ   
catch(Exception e){e.printStackTrace ();} S;#S3?G  
} H^ _[IkuA%  
JR/:XYS+  
((i%h^tGa;  
//读取保存的下载信息(文件指针位置) 8>" vAEf  
private void read_nPos() n}?XFx!%  
{ ,Bh!|H(?L1  
try{ c@d[HstBJ  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .&O}/B  
int nCount = input.readInt(); 61e)SIRz9I  
nStartPos = new long[nCount]; u 0M[B7Q  
nEndPos = new long[nCount]; w"Gci~]bXU  
for(int i=0;i<nStartPos.length;i++) vR$[#`X  
{ uan%j]|q%  
nStartPos = input.readLong(); 1} 1.5[4d  
nEndPos = input.readLong(); &2-dZK  
} wZ7Opm<nt  
input.close(); GSzb  
} -xg$qvK  
catch(IOException e){e.printStackTrace ();} D:`b61sWi_  
catch(Exception e){e.printStackTrace ();} o^P/ -&T  
} ? <b>2j  
@=CN#D12  
Pn:L=*  
private void processErrorCode(int nErrorCode) #- S%aeB  
{ d:08@~#  
System.err.println("Error Code : " + nErrorCode); s;!TB6b@  
} R42+^'af  
v@_}R_pX  
A")F7F31c  
//停止文件下载 .Jk[thyU  
public void siteStop() gaFOm9y.e  
{ #{-l(016y  
bStop = true; 1/b5i8I2 v  
for(int i=0;i<nStartPos.length;i++) Ph@hk0dgr/  
fileSplitterFetch.splitterStop(); CK4C:`YG  
+<#0V!DM  
X2CpA;#;7l  
} ~mAv)JK  
} vjNP  
//负责部分文件的抓取 jz CA2N%  
**FileSplitterFetch.java 4%k{vo5i  
*/ }N @8zB~X  
package NetFox; AlZ]UGf^  
fpd4 v|(  
a=m4)tjk  
import java.io.*; ?T.'  q  
import java.net.*; %x(||cq  
p'SclH[   
 {yXpBS  
public class FileSplitterFetch extends Thread { +5AWX,9,-  
D==C"}J  
mdzUL d5J  
String sURL; //File URL gJ \CT'/  
long nStartPos; //File Snippet Start Position V)|]w[(Y  
long nEndPos; //File Snippet End Position c, IAz  
int nThreadID; //Thread's ID IR_&dWHyc  
boolean bDownOver = false; //Downing is over Whd.AaD\  
boolean bStop = false; //Stop identical PBkTI2 v  
FileAccessI fileAccessI = null; //File Access interface JU>F&g/|  
|aD8  
_k'?eZB  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0Y|"Bo9k  
{ _+B{n^ {  
this.sURL = sURL; l~mC$>f  
this.nStartPos = nStart; }\#u~k!l  
this.nEndPos = nEnd; &/+LY_r'<I  
nThreadID = id; zE,1zBS<  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;T-`~  
} $kAal26z  
W!Qaa(o?  
ZovF]jf k  
public void run() lE=&hba  
{ 7)-uYi] dA  
while(nStartPos < nEndPos && !bStop) ~DJILc  
{ n{*A<-vL  
/#Fz K  
c^F@9{I  
try{ >;s!X(6 b  
URL url = new URL(sURL); $cSmubZK  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u.yjk/jF  
httpConnection.setRequestProperty("User-Agent","NetFox"); I+GP`=\  
String sProperty = "bytes="+nStartPos+"-"; +o3 ZQ9  
httpConnection.setRequestProperty("RANGE",sProperty); ]broU%#"  
Utility.log(sProperty); r]3v.GZy  
xofxE4.  
yd=NafPM  
InputStream input = httpConnection.getInputStream(); {3@"}Eh  
//logResponseHead(httpConnection); r?%,#1|$$  
!Bu=?gf  
7X{@$>+S  
byte[] b = new byte[1024]; ;659E_y>  
int nRead; M`D`-vv  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) w678  
{ Q=u [j|0mc  
nStartPos += fileAccessI.write(b,0,nRead); !QsmT3   
//if(nThreadID == 1) pY$DOr- r`  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F 9J9zs*,  
} [M#I Nm}  
/P[@o  
3kW%,d*_  
Utility.log("Thread " + nThreadID + " is over!"); X,`^z,M%I  
bDownOver = true; R^VmNj  
//nPos = fileAccessI.write (b,0,nRead); 4<btWbk5u*  
} m?y'Y`  
catch(Exception e){e.printStackTrace ();} K<vb4!9Z9  
} fq(3uE]nC  
} ekPn`U  
W61nJ7@  
91oAg[@4G  
//打印回应的头信息 >>.4@  
public void logResponseHead(HttpURLConnection con) ;~"#aL50fe  
{ se S)`@n  
for(int i=1;;i++) F3=iyiz6  
{ Ou5,7Ne  
String header=con.getHeaderFieldKey(i); ' fka?lL  
if(header!=null) 5 8n(fdE  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 115zvW  
Utility.log(header+" : "+con.getHeaderField(header)); Eemk2>iP?  
else iu+rg(*%  
break; ^laf!kIP  
} JN<IMH  
} @DK;i_i  
0OPpALl  
DgRA\[c  
public void splitterStop() G8Sx;Xi  
{ h0n,WU/Kw  
bStop = true; )Qixde>]p  
} [;8vO=Z  
D_-<V,3t  
@Sd l~'"  
} oZ"93]3-  
z 8\;XR  
2[Q/|D}}|  
/* /ng +IC3  
**FileAccess.java [Csv/  
*//文件访问(定位,写) R6/vhze4L2  
package NetFox; V=DT.u  
import java.io.*; 1E|~;wo\  
|"XxM(Dm  
{'R\C5 :D7  
public class FileAccessI implements Serializable{ Lr}>Md  
c<n <!!vi  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <4QOjW  
RandomAccessFile oSavedFile; A-XWG9nL  
long nPos; @Nk]f  
Bm&%N?9  
S|HnmkV66  
public FileAccessI() throws IOException L4C_qb k;:  
{ h,WF'X+  
this("",0); b3RCsIz  
} 8>y!=+9_  
(hv>vfY@  
(aa}0r5  
public FileAccessI(String sName,long nPos) throws IOException 3(/J(8  
{ lqe71](sK8  
oSavedFile = new RandomAccessFile(sName,"rw"); j/+e5.EX/  
this.nPos = nPos; @p}"B9h*^  
oSavedFile.seek(nPos); GDMg.w 4Yk  
} d:V6.7>,  
js#72T/_n  
Z(=U ZI?  
public synchronized int write(byte[] b,int nStart,int nLen) [O52Bn  
{  !Hp H  
int n = -1; "X7;^yY  
try{ KL}o%wfLy  
oSavedFile.write(b,nStart,nLen); Im*~6[  
n = nLen; <.lT.>'?  
} #pvq9fss,}  
catch(IOException e) 6KddHyFz  
{ D ,kxB~  
e.printStackTrace (); r8 9o  
} <K CI@  
T5:Q_o]  
lHM+<Z  
return n; p/Pus;*s  
} Skr (C5T  
r#zcl)rbU  
x}/jh  
} ;\K]~  
$Cz2b/O  
|[`YGA4  
/* h*Fv~j'p  
**SiteInfoBean.java )LGVR 3#  
*/ :E9pdx+  
package NetFox; T AG@Ab  
ad}8~6}_&  
o;@~uU  
public class SiteInfoBean { aM~IRLmK  
NK0'\~7&  
3t-STk?  
private String sSiteURL; //Site's URL 7Fj8Mp|  
private String sFilePath; //Saved File's Path 8dR `T}  
private String sFileName; //Saved File's Name q/@2=$]hH3  
private int nSplitter; //Count of Splited Downloading File lC($@sC%  
NtM>`5{?  
YE`Y t  
public SiteInfoBean() 0OO[@Ht  
{//nSplitter的缺省值为5 "qgwuWbM  
//default value of nSplitter is 5 jL-2 }XrA  
this("","","",5); qur2t8gnxq  
} lie,A  
,zgz7  
,sitOy}ks  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) NgTB4I 8P  
{ +,,(8=5 g  
sSiteURL= sURL; /4T6Z[=s  
sFilePath = sPath; ( v*xW.  
sFileName = sName; kWW2N0~$  
this.nSplitter = nSpiltter; #LR4%}mg  
5Npxs&Ea  
&dtst??  
} 'I>USl3hI  
# Wi?I =,  
uH*6@aYPo  
public String getSSiteURL() $ 64up!  
{ Q yw@ r  
return sSiteURL; =mXC,<]  
} U~D~C~\2;  
q=pRe-{  
a <C?- g|  
public void setSSiteURL(String value) L2>e@p\>  
{ Xqw}O2QQ1  
sSiteURL = value; Z3JUYEAS  
} qFWN._R  
 ,]EhDW6  
X$5  
public String getSFilePath() :.5l  
{ P<IDb%W  
return sFilePath; TVcA%]y{;  
} d3:GmB .  
l Xa/5QKC  
IW~wO  
public void setSFilePath(String value) A1/@KC"&{G  
{ US$$ADq  
sFilePath = value; P] *x6c^n  
} "r46Rfa  
>OaD7  
Y'iI_cg  
public String getSFileName() WGz)-IB!PE  
{ by<@\n2B:U  
return sFileName; hnFpC1TO  
} 8;?4rrS  
~1+6gG  
GqHW.s5  
public void setSFileName(String value) Mw0>p5+ cy  
{ Nbr$G=U  
sFileName = value; <-k!  
} G$f%]A1  
dJgLS^1E  
e4` L8  
public int getNSplitter() #VrIU8Q7'  
{ ;(?tlFc  
return nSplitter; o{y}c->  
} *#YZm>h   
qA GjR!=^  
D#LV&4e>.E  
public void setNSplitter(int nCount) uj6'T Sl  
{ ]^C 8Oh<  
nSplitter = nCount; bq ED5;d'#  
} ! $$>D"  
} zzZ EX  
&MSU<S?1  
{[2o  
/* % [$HX'Y  
**Utility.java M,fL(b;2  
*/ MOD&3>NI  
package NetFox; Zkd{EMW  
I&+.IK_  
X8*g#lO?  
public class Utility { ~`AB-0t.u  
$/M-@3wro  
[1vm~w'  
public Utility() -i8KJzPL f  
{ &DMC\R*j  
`2 <:$]  
-LiGO#U  
} ~Y/A]N86,  
QH-CZ6M  
//线程睡眠 E /H%q|q  
public static void sleep(int nSecond) tQ9%rb  
{ hH`x*:Qja  
try{ nNCR5&,q  
Thread.sleep(nSecond); FFqK tj's  
} *5PQ>d G  
catch(Exception e) } [#8>T  
{ hq7f"`  
e.printStackTrace (); ]W?cy  
} U(f@zGV  
} f![] :L  
z[f]mU  
//日志 %AO6 =  
public static void log(String sMsg) zls^JTE  
{ STnMBz7  
System.err.println(sMsg); <~dfp  
} "zq'nV=  
eF%M2:&c;  
:XY%@n  
public static void log(int sMsg) KF'fg R  
{ R%3yxnM*  
System.err.println(sMsg); }K)A jZ  
} f$>_>E  
} qR.FjQOvn  
iOZ9A~Ywy  
~+'f[!^  
/* h^(U:M=A  
**TestMethod.java ]izHn;+  
*/ X.#*+k3s0  
package NetFox; cgG*7E  
Ou1kSG|kM  
O + aK#eF  
public class TestMethod { C+/EPPi  
n*9QSyJN]  
l0G{{R 0Y  
public TestMethod() drAJ-ii  
{ ///xx/weblogic60b2_win.exe "S#$:92  
try{ Ei:m@}g  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); B-LV/WJ_  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); UhJS=YvT  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0i}.l\  
fileFetch.start(); bDDP:INm.  
} Vb? wwx7=  
catch(Exception e){e.printStackTrace ();} /HUT6B  
2(!W 9#]  
fP<== DK  
} }N9PV/a  
J <z ^C  
c<Ud[x.  
public static void main(String[] args) '19?  
{ vwAhNw2-  
new TestMethod(); +~1FKLu  
} 6xr%xk2E  
} -`X`Ff  
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