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http断点续传简单实现(java)

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/* ZwerDkd  
**SiteFileFetch.java 3LTcEd  
*/ (N=5 .7"T  
package NetFox; { e5/+W  
import java.io.*; tP%{P"g3^  
import java.net.*; -cm$[,b6  
g{9+O7q  
-,{-bi  
public class SiteFileFetch extends Thread { ]B]*/  
]$\|ktY!  
j$Je6zq0x  
SiteInfoBean siteInfoBean = null; //文件信息Bean ,SiY;(b=\  
long[] nStartPos; //开始位置 U*P. :BvG  
long[] nEndPos; //结束位置 *(>}Y  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 dG71*)<)t  
long nFileLength; //文件长度 }sFm9j7yR  
boolean bFirst = true; //是否第一次取文件 Iu *^xn  
boolean bStop = false; //停止标志 C 2w2252T  
File tmpFile; //文件下载的临时信息 5W@jfh)  
DataOutputStream output; //输出到文件的输出流 v[n7"  
D.6,VY H  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) w L^%w9q-  
public SiteFileFetch(SiteInfoBean bean) throws IOException l-$uHHyu*  
{ D^;*U[F?  
siteInfoBean = bean; 6q6FB  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); iTg;7~1pY  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); @b3#X@e}  
if(tmpFile.exists ()) }Lw>I94e  
{ c9nH}/I_  
bFirst = false; .ol'.t ,S  
read_nPos(); T!}[yW  
} {?}*1,I  
else *8tI*Pus  
{ cFF*Z=L _  
nStartPos = new long[bean.getNSplitter()]; 79yd&5#e?  
nEndPos = new long[bean.getNSplitter()]; 5+jf/}t A  
} d@3}U6,  
!;!~n`  
b2b75}_A  
+ EM_TTf4  
} Y05P'Q  
}/,CbKi,+  
on7I l  
public void run() oq_6L\ ~  
{ EIf ~dOgH  
//获得文件长度 \OpoBXh  
//分割文件 *I?Eb-!t  
//实例FileSplitterFetch T4;T6 9j;,  
//启动FileSplitterFetch线程 _ZAchzV  
//等待子线程返回 ;|cTHGxbE  
try{ rBN)a"  
if(bFirst) G^1b>K  
{ " uPy,<l  
nFileLength = getFileSize(); `:G%   
if(nFileLength == -1) z>[tF5  
{ 5')8r ';,  
System.err.println("File Length is not known!"); 9ElCg"  
} uGl| pJ\y=  
else if(nFileLength == -2) @E53JKYhY  
{ P~FUS%39"o  
System.err.println("File is not access!"); :9|W#d{o  
} j` /&r*zNq  
else [;b=A  
{ kV Rn`n0  
for(int i=0;i<nStartPos.length;i++) /+3a n9h  
{ N6[i{;K@N{  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Gj /3kS~@  
} jUqy8q&  
for(int i=0;i<nEndPos.length-1;i++) ? QDWuPhN  
{ PZD>U)M  
nEndPos = nStartPos[i+1]; rB%$;<`/  
} =N|kn<h4  
nEndPos[nEndPos.length-1] = nFileLength; 8%~t  
} VIR.yh  
} 5ZAb]F90  
Q^Bt1C  
D["MUB4l  
//启动子线程 jRpdft  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2~;&g?T6  
for(int i=0;i<nStartPos.length;i++) 0%;146.p  
{ ^aRgMuU  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~ekh1^evu  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), vY*\R0/a  
nStartPos,nEndPos,i); Yp4c'Zk  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *V;3~x!  
fileSplitterFetch.start(); gK3Mms]}m  
} - n6jG}01b  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RX2{g^V7  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); pD@zmCU  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", i$-#dc2qY  
nEndPos = " + nFileLength); sst,dA V$  
// fileSplitterFetch[nPos.length-1].start(); HpexH{.u)  
Ok%}|/ P4  
'?GQ~Bf<>  
//等待子线程结束 ELh3 ^  
//int count = 0; kYxS~Kd<  
//是否结束while循环 ER{3,0U  
boolean breakWhile = false; $'[q4wo<  
 \`xkp[C  
*,\` o~  
while(!bStop) P l{QOR  
{ 9''p[V.3  
write_nPos(); 1:= `Y@.S  
Utility.sleep(500); w9#R'  
breakWhile = true; xnq><4  
qA/bg  
^i:\@VA:  
for(int i=0;i<nStartPos.length;i++) ]R_G{%  
{ ev>oC~>s  
if(!fileSplitterFetch.bDownOver) {sC=J hs-  
{ fV ZW[9[  
breakWhile = false; |Zq\GA  
break; rvwy~hO"  
} M>_= "atI  
} I/UQ'xx  
if(breakWhile) 77 :'I  
break; 8kW/DcLE  
%TK&)Q% h5  
O=jN&<rb  
//count++; DPJh5d  
//if(count>4) 5su.+4z\  
// siteStop(); f(u&XuZ  
} ]RFdLV?  
g<[rH%\6fg  
dA#{Cn;  
System.err.println("文件下载结束!"); Y~"9L|`f/  
} Ud3""C5B  
catch(Exception e){e.printStackTrace ();} N5 q725zJ  
} ZcZ;$*  
j.QHkI1.  
z*.v_Mx  
//获得文件长度 "j Zm0U$,*  
public long getFileSize() Qm);6X   
{ cj(X2L  
int nFileLength = -1; YlUpASW  
try{ <FmBa4ONU  
URL url = new URL(siteInfoBean.getSSiteURL()); XS0V:<+,  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^&:'NR  
httpConnection.setRequestProperty("User-Agent","NetFox"); O2H/rFx4  
FWTx&Ip  
MtG_9-  
int responseCode=httpConnection.getResponseCode(); jpO38H0)  
if(responseCode>=400) r69WD .  
{ cTj~lO6  
processErrorCode(responseCode); V<$*Y>;  
return -2; //-2 represent access is error [$2qna2VP  
} t&"5dM\  
2xmT#m  
<PD|_nZT  
String sHeader; HtzMDGV<  
qWB%),`j>  
q 22/_nSC  
for(int i=1;;i++) %}F"*.  
{ zPQ$\$7xB  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); om7`w ]  
//Utility.log(in.readLine()); D9ywg/Q91  
sHeader=httpConnection.getHeaderFieldKey(i); bhKV +oN  
if(sHeader!=null) slSR=XOG  
{ zH+<bEo=1=  
if(sHeader.equals("Content-Length")) P|N?OocE  
{ tQ0=p| T]  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]hUKuef  
break; ? -{IsF^  
} )[DpK=[N^p  
} ;xW{Ehq-h  
else eG^z*`**  
break; /'Bdq?!B&  
} /\~W$.c  
} M,L@k  
catch(IOException e){e.printStackTrace ();} +UaO<L  
catch(Exception e){e.printStackTrace ();} dP3VJ3+ %  
t~~r-V":  
kGj]i@(PA4  
Utility.log(nFileLength); o*)@oU  
drX4$Kdf]  
&z0iLa4q)  
return nFileLength; r!M#7FDs(  
} vz,LF=s2  
P6E1^$e  
ok=40B99T  
//保存下载信息(文件指针位置) ={xqNRVd  
private void write_nPos() '5cZzC 2  
{ feg`(R2  
try{ dp< au A  
output = new DataOutputStream(new FileOutputStream(tmpFile)); | /#'S&!U  
output.writeInt(nStartPos.length); ;q&Z9 lm  
for(int i=0;i<nStartPos.length;i++) [EOMCH2Ki  
{ w}b<D#0XC  
// output.writeLong(nPos); GFY-IC+fc  
output.writeLong(fileSplitterFetch.nStartPos); 'Ix5,^M}B  
output.writeLong(fileSplitterFetch.nEndPos); g$gVm:=  
} V*kznm  
output.close(); d'q;+ jnP  
} R]VTV7D  
catch(IOException e){e.printStackTrace ();} |3|wdzV  
catch(Exception e){e.printStackTrace ();} o5V`'[c  
} iGyVG41U  
4Q/r[x/&C  
A<;0L . J  
//读取保存的下载信息(文件指针位置) I &cX8Tw  
private void read_nPos() e Ri!\Fx  
{ _jk|}IB;X  
try{ ]t7ClT)n!  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); w=gQ3j#s  
int nCount = input.readInt(); PgqECd)f  
nStartPos = new long[nCount]; |/2LWc?  
nEndPos = new long[nCount]; {!g?d<*  
for(int i=0;i<nStartPos.length;i++) Xv]*;Bq:SK  
{ hX %s]"  
nStartPos = input.readLong(); +%x^RV}  
nEndPos = input.readLong(); 4KZSL: A  
} >5df@_'  
input.close(); w4`!Te  
} `GP3 D~  
catch(IOException e){e.printStackTrace ();}  Ckw83X  
catch(Exception e){e.printStackTrace ();} S{Rh'x\B  
} frk7^5  
8QPT\~  
U=M#41J  
private void processErrorCode(int nErrorCode) )ZviS.  
{ UVnrDhd!0  
System.err.println("Error Code : " + nErrorCode); Za34/ro/T  
} -wBnwn-  
0\QYf0o   
|@OJ~5H/{  
//停止文件下载 JPHUmv6  
public void siteStop() a{5H33JA  
{ .!!79 6hS  
bStop = true; q^u6f?B  
for(int i=0;i<nStartPos.length;i++) z{@= _5;  
fileSplitterFetch.splitterStop(); A"`L~|&  
%~ ;nlDw  
kA1f[ AL  
} ,7QBJ_-;QJ  
} Xk 5oybDI  
//负责部分文件的抓取 @_G` Ok4  
**FileSplitterFetch.java B<rPvM7a  
*/ rrW! X q  
package NetFox; !Jh*a *I}  
BllDWKb  
q`h7H][(A  
import java.io.*; ry z /rf  
import java.net.*; x0y% \  
cvn-*Sj  
(}VuiNY<3  
public class FileSplitterFetch extends Thread { U[blq M  
@F>[DW]O  
`>dIF.  
String sURL; //File URL qT 5Wa O)  
long nStartPos; //File Snippet Start Position YL; SxLY  
long nEndPos; //File Snippet End Position ,ZLG7e  
int nThreadID; //Thread's ID }3bQ>whF  
boolean bDownOver = false; //Downing is over K lPm=  
boolean bStop = false; //Stop identical U$MWsDn   
FileAccessI fileAccessI = null; //File Access interface [B.W1 GL!  
pq%t@j(X  
wEZqkV  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException p!.  /  
{ F%w\D9+P  
this.sURL = sURL; ftDVxKDE?S  
this.nStartPos = nStart; e-&L\M  
this.nEndPos = nEnd; GZ; Z  
nThreadID = id; <m-Ni  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 hB?U5J  
} k?!TjBKm  
kO /~i  
/W7&U =d9  
public void run() aY3pvOV  
{ s{b0#[  
while(nStartPos < nEndPos && !bStop) `[w}hFl~q  
{ 2l]C55p)s  
:-W$PIBe  
JDIz28Ww  
try{ VGq{y{(  
URL url = new URL(sURL); pT|./ Fe  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H&"_}  
httpConnection.setRequestProperty("User-Agent","NetFox"); s0x@ u  
String sProperty = "bytes="+nStartPos+"-"; kfH9Y%bOy  
httpConnection.setRequestProperty("RANGE",sProperty); !NlB%cF  
Utility.log(sProperty); ]W89.><%14  
Y}eZPG.h  
;igE IGR  
InputStream input = httpConnection.getInputStream(); >$d d 9|[  
//logResponseHead(httpConnection); J@=!w[v+  
$`cy'ZaF  
@B}&62T  
byte[] b = new byte[1024]; Yb,G^+;  
int nRead; W\d0  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^XjvJa  
{ j@kRv@  
nStartPos += fileAccessI.write(b,0,nRead); EBN]>zz  
//if(nThreadID == 1) BxW||O|_N"  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =|DkD- O  
} $i5G7b  
s.k`];wo  
_rWTw+ L  
Utility.log("Thread " + nThreadID + " is over!"); (7 ]\p  
bDownOver = true; {Tjtj@-  
//nPos = fileAccessI.write (b,0,nRead); *X"F:7  
} 2n"*)3Qj  
catch(Exception e){e.printStackTrace ();} X.r!q1_c  
} VLl&>Pbe-  
} [U+<uZzOC  
2/a04qA#  
x_>"Rnv:K  
//打印回应的头信息 see'!CjVo2  
public void logResponseHead(HttpURLConnection con) "N=&4<]I5  
{ :6HiP&<  
for(int i=1;;i++) z^SN#v$  
{ TLR Lng  
String header=con.getHeaderFieldKey(i); ul]m>W  
if(header!=null) $)WH^Ir~  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); d@`-!"  
Utility.log(header+" : "+con.getHeaderField(header)); qrORP3D@  
else <3J=;.\6  
break; d- _93  
} kG~ivB}x  
} "X!_37kQ  
-&HoR!af  
"1pZzad  
public void splitterStop() ZFd{q)qe   
{ `rRg(fCN!M  
bStop = true; g]TI8&tP!L  
} fitK2d   
[jmAMF<F  
+L<w."WG  
} 9h)P8B.>M  
).@)t:uNa  
!*$'fn'bAA  
/* ! Dhfr{  
**FileAccess.java eQ4B5B%j/x  
*//文件访问(定位,写) \t 7zMp  
package NetFox; +q>C}9s3  
import java.io.*; &  t @  
x Ps& CyI  
*jqPKK/  
public class FileAccessI implements Serializable{ '!2  
'j =PbA  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9EY_R&Yq%  
RandomAccessFile oSavedFile; >LRaIU>  
long nPos; r>D[5B  
]mDsUZf<  
#|2g{7 g*  
public FileAccessI() throws IOException DrYoC7   
{ 9Y*VzQE  
this("",0); kA->xjk  
} =V4_DJ(&  
(Nve5  
1QdB`8in  
public FileAccessI(String sName,long nPos) throws IOException j4hUPL7  
{ ,_7tRkn  
oSavedFile = new RandomAccessFile(sName,"rw"); r+WPQ`Ar  
this.nPos = nPos; [zO(V`S2  
oSavedFile.seek(nPos); <\#  
} ^SelqX  
6!Ap;O^*  
d+wNGN  
public synchronized int write(byte[] b,int nStart,int nLen) Z6HkQ=A64  
{ . KSr@Gz  
int n = -1; (\[!,T"[  
try{ EEnTq  
oSavedFile.write(b,nStart,nLen); $f@-3/V6{  
n = nLen; 0yEyt7 ~@  
} )a2m<"  
catch(IOException e) GA*Khqdid  
{ & ;x1Rx  
e.printStackTrace (); &|,qsDK(  
} OEqe^``!  
97@?QI}  
`Rub"zM  
return n; +AhR7R!  
} T;XEU%:LK  
@s}I_@  
QZ$94XLI  
} BC ]^BKP  
A,ttn5Sh?  
^0_*AwIcN  
/* bg[k8*.:F  
**SiteInfoBean.java 'Cd8l#z7  
*/ =;-/( C  
package NetFox; `r e]Q0IO  
@vh3S+=M  
\$}xt`6p  
public class SiteInfoBean { OD-CU8X9  
B q+RFo  
^n!{ vHz  
private String sSiteURL; //Site's URL iJv4%|9  
private String sFilePath; //Saved File's Path b#(SDNo6  
private String sFileName; //Saved File's Name iT1"Le/N  
private int nSplitter; //Count of Splited Downloading File c[}h( jkP  
C '4u+raq  
B$1nq#@  
public SiteInfoBean() 1k6f|Al -  
{//nSplitter的缺省值为5 Wp/!;  
//default value of nSplitter is 5 H0Qpc<Z4/  
this("","","",5); R/R[r> 1)6  
} \[Op:^S  
Vy.A`Hz  
gV1&b (h  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4- ^|e  
{ ;2q;RT`h  
sSiteURL= sURL; M p:c.  
sFilePath = sPath; M8X*fYn  
sFileName = sName; /tM<ois*  
this.nSplitter = nSpiltter; K++pH~o  
4Z)`kS} =]  
$6}siU7s4  
} EGO;g^,  
)_"Cz".|9  
UeV2`zIg`  
public String getSSiteURL() D-\\L[  
{ mVfg+d(  
return sSiteURL; ]|18tVXc  
} 4j|]=58  
+8Yt91   
1fM= >Z  
public void setSSiteURL(String value) z)xGZ*{=  
{ H$au02dpU  
sSiteURL = value; ks< gSCB  
} 4SCb9| /Q  
]IMBRZQqb  
fqZqPcT0  
public String getSFilePath() hAi50q;z  
{ )[yM4QFl  
return sFilePath; u6IEBYG ((  
} \!j{&cJ  
S9d+#6rn  
gm~Ka%O|F  
public void setSFilePath(String value) NX&mEz  
{ (`x6QiG!  
sFilePath = value; ZfM(%rx  
} y5B4t6M(  
v/=O:SM}  
G 5w:  
public String getSFileName() QE[ETv  
{ 6 DqV1'  
return sFileName; &MsnQP  
} V^B'T]s  
U4qp?g+:  
L$6{{Tw"2  
public void setSFileName(String value) :$."x '  
{ Ar7vEa81  
sFileName = value; L^3~gZ  
} ,u7: l  
!q=ej^(S  
%myg67u  
public int getNSplitter()  x9XQ  
{ u'M \m7  
return nSplitter; |K| c  
} s <Pk[7`*  
]n1@!qa48  
^d Fdw\  
public void setNSplitter(int nCount) ag^EH"%zw  
{ r7o63]  
nSplitter = nCount; G/>upnA{w  
} Zc(uK{3W-  
} wG6>.`:  
hd1(q33  
Z12-Vps  
/* w^EAk(77  
**Utility.java 0FD#9r  
*/ 4CVtXi_Y  
package NetFox; ?RJ ) u  
pt<!b0G  
&Q 7Q1`S  
public class Utility { +pp|Qgr 3  
=UYZ){rt9E  
v?BX 4FO  
public Utility() hZf0q 2  
{ (@@t,\iF  
S"0<`{Gv  
3<sYxA\?w  
} IOmQ1X7,  
Q$Qs$  
//线程睡眠 VCfa<hn  
public static void sleep(int nSecond) U|VF zpJ  
{ 2Sbo7e  
try{ B'"(qzE-kM  
Thread.sleep(nSecond); T#%r\f,l0  
} Y ]&D;w  
catch(Exception e) swV/M i>  
{ {^zieP!  
e.printStackTrace (); Y5 e6|b|  
} D_er(  
} rKg~H=4x2  
.si!`?K%[  
//日志 0J7)UqMf.  
public static void log(String sMsg) ,pL%,>R5  
{ > 5-z"f  
System.err.println(sMsg); G6wBZ?)k  
} !j[Oy r|  
Bc3(xI'>J  
|2w,Np-  
public static void log(int sMsg) ,?g}->ZB  
{ HLm6BtE  
System.err.println(sMsg); ]FV,}EZ  
} 6cH.s+  
} &6 .r=,BO  
gz8>uGx&V!  
`Mx&,;x  
/* at"-X?`d  
**TestMethod.java e]F4w(*=  
*/ ZdG?fWWA  
package NetFox; .`qw8e}y#'  
x&>zD0\ :\  
Q${0(#Nu  
public class TestMethod { =yo?]ZS  
\`3YE~7J/  
"cSH[/  
public TestMethod() V ':?rEN|  
{ ///xx/weblogic60b2_win.exe zzOc # /  
try{ yg34b}m{  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); B>sSl1opI  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); yneIY-g(p  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 40,u(4.m*  
fileFetch.start(); k\(LBZ"vR  
} pJ)PVo\cV  
catch(Exception e){e.printStackTrace ();} b.HfxYt(  
}4G/x;D  
O6JH)Ka"S  
} j"g[qF/*  
NKyaR_q`  
O#Y;s;)i"  
public static void main(String[] args)  <sdC#j  
{ 17IT:T,'  
new TestMethod(); oAaUXkQE  
} e(nT2E  
} #+$pE@u7A  
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