http断点续传简单实现（java)

/* OT-!n  
**SiteFileFetch.java 15PFnk6E|  
*/ JBX#U@k>I  
package NetFox; {|)u).n|  
import java.io.*; }py6H[  
import java.net.*; [X>\!mt  
$@]tTz;b  
_m3}0q  
public class SiteFileFetch extends Thread { :9`'R0
=i^  
llG^+*Y8t  
+bC-_xGuh  
SiteInfoBean siteInfoBean = null; //文件信息Bean !=%E&e]  
long[] nStartPos; //开始位置 yVds2J'w-  
long[] nEndPos; //结束位置 QUa_gYp0v  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 qm30,$\c`~  
long nFileLength; //文件长度 o#(z*v@  
boolean bFirst = true; //是否第一次取文件 8j~:p!@  
boolean bStop = false; //停止标志 +)8,$1[p|  
File tmpFile; //文件下载的临时信息 jY^wqQls  
DataOutputStream output; //输出到文件的输出流 88c-K{}3  
2de[ yz  
//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） QEd>T"@g  
public SiteFileFetch(SiteInfoBean bean) throws IOException :5kgJu  
{ &E98&[`7  
siteInfoBean = bean; GS),rNBur  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); > Y7nq\  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); BLc&q)  
if(tmpFile.exists ()) GL4-v[]6I  
{ BI9~%dm  
bFirst = false; 77y_?di^I  
read_nPos(); kaSi sjd  
} @ s   
else h4@v.GI  
{ InI^,&<  
nStartPos = new long[bean.getNSplitter()]; WH`E=p^x4  
nEndPos = new long[bean.getNSplitter()]; pUs:r0B  
} 9OIX5$,S;  
v=n'#:k  
@WcK<Qho  
(W*~3/@D  
} {\tHS+]  
^A9D;e6!-  
K(*QhKX  
public void run() %EC{O@EAk  
{
w-~
u[c  
//获得文件长度 \9[_*  
//分割文件 8J60+2Wa  
//实例FileSplitterFetch #ma#oWqF}  
//启动FileSplitterFetch线程 +h!OdWD9
 
//等待子线程返回 jVh I`F{n  
try{ Obl']Hr{y9  
if(bFirst) V0'T)  
{ RRYm.dMIw  
nFileLength = getFileSize(); `o7m)T')  
if(nFileLength == -1) 'G3;!xk$  
{ :\ %.x3T'  
System.err.println("File Length is not known!"); ^4jIT1  
} f? sW^d;  
else if(nFileLength == -2) Z<j(ZVO  
{ gO C5  
System.err.println("File is not access!"); li>`9qCm
I  
} O0`k6$=6r  
else o+U]=q*|)$  
{ B~p` 3rC  
for(int i=0;i<nStartPos.length;i++) "2cJ'n/L  
{ d'1L#`?  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 7
"L`|O?8)  
} ^:JZ.r  
for(int i=0;i<nEndPos.length-1;i++) -8-BVU  
{ XS!mtd<q  
nEndPos = nStartPos[i+1]; Qg dHIMY  
} YHoj^=/b  
nEndPos[nEndPos.length-1] = nFileLength; EH;w <LvT  
} L,I5/K6  
} -C9_gZ  
x)'4u6;d  
etY/K0  
//启动子线程 {?-@`FR-  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g.CUo:c  
for(int i=0;i<nStartPos.length;i++) $`J'Y>`  
{ C)2Waj}  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), JaC =\\B  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :5/P{Co(  
nStartPos,nEndPos,i); k!/"J ;  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zbL!q_wO  
fileSplitterFetch.start(); 8"2 Y$*)(  
} 6
#NptXB  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), b>R/=tx  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !L3M\Q0  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", cE7xNZ;Bh  
nEndPos = " + nFileLength); FB<#N+L\  
// fileSplitterFetch[nPos.length-1].start(); zB6u%uWR  
}P[xZ_S1  
kNX"Vo]1  
//等待子线程结束 :*GLLjS;  
//int count = 0; igNZe."V  
//是否结束while循环 2i+'?.P  
boolean breakWhile = false; &<</[h/B/F  
~T<yp  
Aj`zT
'  
while(!bStop) kj(Ko{  
{ INQ0h`T  
write_nPos(); EYc, "'  
Utility.sleep(500); _c}@Fi+E  
breakWhile = true; R-Y|;  
*&VH!K#@{  
ZVo%ssVt  
for(int i=0;i<nStartPos.length;i++) chjXsq#Q^  
{ "zSi9]j  
if(!fileSplitterFetch.bDownOver) &Nx'Nq
9y  
{ XW!a?aLNX  
breakWhile = false; k(n{$  
break; &m=Xg(G~c  
} G\8ps~3T  
} OoKzPePWji  
if(breakWhile) LqnN5l@_B  
break; QN=a{  
&h=O;?dO  
:[#g_*G@p  
//count++; #V4kT*2P)  
//if(count>4) cU\Er{ k  
// siteStop(); <{rRcFR  
} kz]vXJ  
z@E-pYV  
hX#s3)87  
System.err.println("文件下载结束！"); J)O1)fR  
} 3eUTV<!  
catch(Exception e){e.printStackTrace ();} _D9`L&X}  
} ^4@~\#$z  
vywd&7gK  
Do@:|n  
//获得文件长度  SJY<#_b  
public long getFileSize() R["2kEF  
{ +QNFu){G  
int nFileLength = -1; $~UQKv>  
try{ %JBFG.+  
URL url = new URL(siteInfoBean.getSSiteURL()); +hdD*}qauC  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %GUu{n<6  
httpConnection.setRequestProperty("User-Agent","NetFox"); \VmqK&9   
8D[8(5  
sW)C6 #  
int responseCode=httpConnection.getResponseCode(); j-2`yR  
if(responseCode>=400) @=o1q=5@8  
{ Q9X7-\n  
processErrorCode(responseCode); bSmF"H0cP  
return -2; //-2 represent access is error ,: X+NQ  
} /{pVYY  
eto3dJ!R  
9g3J{pKcZ  
String sHeader; ~YO-GX(  
p"4i(CWGS  
k$</7IuH  
for(int i=1;;i++) ra\Moy  
{ mG[S"?C  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); uSSnr#i^j  
//Utility.log(in.readLine()); iTTe`Zr5y  
sHeader=httpConnection.getHeaderFieldKey(i); [9f TN2'z  
if(sHeader!=null) k8^!5n  
{ aaq{9Y#  
if(sHeader.equals("Content-Length")) (p<
QRb:&Z  
{ '| Enc"U  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <VD^f  
break; &0*l=!:G^  
} }J}a;P4  
} 7 }`c:u~j  
else qJQE|VM&  
break; [Af&K22M(X  
} &wRdUIc  
} $"[1yQ<p  
catch(IOException e){e.printStackTrace ();} P+pL2BA  
catch(Exception e){e.printStackTrace ();} mIVnc`3s  
X%W_cb2  
O@[c
*3]e  
Utility.log(nFileLength); |fdr\t#'~  
}^uUw&   
=ECw'  
return nFileLength; &Im{p7gf!b  
} ")|3ZB7>*  
WrhC q6  
+}c '4hRv  
//保存下载信息（文件指针位置） 4,L(  
private void write_nPos() 65bLkR{0  
{ ?Dro)fH1  
try{ ,]@K6  
output = new DataOutputStream(new FileOutputStream(tmpFile)); q;3,}emg  
output.writeInt(nStartPos.length); e*_8B2da  
for(int i=0;i<nStartPos.length;i++) %+oWW5
q7  
{ dsP|j(y  
// output.writeLong(nPos); xQ4D| &  
output.writeLong(fileSplitterFetch.nStartPos); g|*2O}<  
output.writeLong(fileSplitterFetch.nEndPos); QjETu  
} !=C4=xv  
output.close(); <)y44x|S'  
} 2SU G/-P#  
catch(IOException e){e.printStackTrace ();} Q\G8R^9j p  
catch(Exception e){e.printStackTrace ();} f!;i$Oif  
} BQ
WEC,*N  
YK*2
 
a,o)i8G9R<  
//读取保存的下载信息（文件指针位置） 2V
(ye9  
private void read_nPos() J 2%^%5&0  
{ !*\)7D  
try{ 0gPz|v>z  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ($*bwqp]}  
int nCount = input.readInt(); M.1b
RB  
nStartPos = new long[nCount]; 3#R~>c2  
nEndPos = new long[nCount]; X}'3N'cbkU  
for(int i=0;i<nStartPos.length;i++) @O+yxGA  
{ }h<\qvCcU  
nStartPos = input.readLong(); 8[(eV.  
nEndPos = input.readLong(); h.c<A{[I6c  
}  r(pp =  
input.close(); :T3I"  
} ) Ph.  
catch(IOException e){e.printStackTrace ();} k$kq|  
catch(Exception e){e.printStackTrace ();} xB:,l'\G  
} log{jF  
GL&ri!,  
f9H;e(D9]  
private void processErrorCode(int nErrorCode) !\Jj}iX3_  
{ 8}Rwf?B  
System.err.println("Error Code : " + nErrorCode); fI}Z`*  
} %?+A.0]E  
Z"Z&X0Oj  
F7J-@T<  
//停止文件下载 &,+G}  
public void siteStop() `*e',j2}UU  
{ <4}zl'.  
bStop = true; /b,M492  
for(int i=0;i<nStartPos.length;i++) B9|!8V  
fileSplitterFetch.splitterStop(); L*bUjR,C  
E^L  
fV*x2g7w  
} Ous[{"-J  
} F.c`0u;=  
//负责部分文件的抓取 bTZ/$7pp9  
**FileSplitterFetch.java =]E(iR_&  
*/ I=l() ET=  
package NetFox; 6gwjrGje\  
{55{YDqx  
)c5M;/s  
import java.io.*; tu6oa[s  
import java.net.*; RL |.y~  
9Q-/Yh  
3 D,PbAd  
public class FileSplitterFetch extends Thread { '-3AWBWI1  
!>b>"\b  
i`7{q~d=  
String sURL; //File URL iaXNf ])?  
long nStartPos; //File Snippet Start Position P{5p'g ,  
long nEndPos; //File Snippet End Position t,= ta{ a  
int nThreadID; //Thread's ID CJg &  
boolean bDownOver = false; //Downing is over T+NEw8C?/  
boolean bStop = false; //Stop identical w
xpD{P  
FileAccessI fileAccessI = null; //File Access interface 6~?7CK  
C
yO2Z  
rklr^ e  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3;~1rw=$<  
{ o%X_V!B{V  
this.sURL = sURL; 4IG=mG)  
this.nStartPos = nStart; >x@]wsj  
this.nEndPos = nEnd; X!&DKE  
nThreadID = id; %1SA!1>j  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 aq~hl7MTj  
} 8#'<SB  
hXM8`iFW5  
~\4l*$3(^  
public void run() )v;>6(  
{ AuUT 'E@E  
while(nStartPos < nEndPos && !bStop) @Ek''a$  
{ m9ts&b+TE  
Xhtc0\0"(  
*c7kB}/  
try{ %]nYv#K  
URL url = new URL(sURL); @=`Dw/13  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,0NVb7F;k  
httpConnection.setRequestProperty("User-Agent","NetFox"); z*ZEw  
String sProperty = "bytes="+nStartPos+"-"; 2\l7=9 ]\3  
httpConnection.setRequestProperty("RANGE",sProperty); pl Ii  
Utility.log(sProperty); KCJ zE>  
</tiNc  
Gnp,~F"  
InputStream input = httpConnection.getInputStream(); GjE/!6b  
//logResponseHead(httpConnection); *XS@Ku   
P482D)  
?l`DkUo*j  
byte[] b = new byte[1024]; [J\5DctX;c  
int nRead; }M?GqA=  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) sY7:Lzs.,  
{ D/:~#)  
nStartPos += fileAccessI.write(b,0,nRead); QR2J;Oj_  
//if(nThreadID == 1) " jn@S-  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7oA$aJQ  
} "UKX~}8T
 
n|lXBCY7K  
h'^7xDw  
Utility.log("Thread " + nThreadID + " is over!"); 2/=CrK  
bDownOver = true; K6~N{:.s  
//nPos = fileAccessI.write (b,0,nRead); ??=CAU%\  
} /ivt8Uiw  
catch(Exception e){e.printStackTrace ();} #9EpQc[4  
} GV6!
`@<  
} W*;~(hDz  
.3qaaXeH  
suj? e6  
//打印回应的头信息 GBtBmV/`  
public void logResponseHead(HttpURLConnection con) '@2pOq  
{ 5[`!\vCiZ  
for(int i=1;;i++) \6)l(b;  
{ Y oNg
3  
String header=con.getHeaderFieldKey(i); T nA
d!  
if(header!=null) o4o&}  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); s#;|8_L M  
Utility.log(header+" : "+con.getHeaderField(header)); ncb
?iJ/b^  
else \ 
  
break; +N"A5U  
} 5FtbZ1L  
} zCL/^^#  
|@]J*Kh  
=+~e44!~D  
public void splitterStop() bM_Y(TgJ  
{ f%ZqK_CW  
bStop = true; [0yKd?e  
} hEsCOcEG  
YZ:YYcr  
C/"fS#<  
} w4:S>6X  
]p(+m_F  
epCU(d*b  
/* x?KgEcnw2X  
**FileAccess.java {2
R b^K  
*//文件访问(定位，写) T=:O(R1*0  
package NetFox; \:8~na+(  
import java.io.*; /tc*jXB  
dn$1OhN8M  
QO
lm#S  
public class FileAccessI implements Serializable{ "^ydoRZ  
Wd_bDZQ  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Bt[`p\p@  
RandomAccessFile oSavedFile; &BqRyUM$F  
long nPos; ,IA0n79  
+8."z"i3lE  
r|:|\"Yk  
public FileAccessI() throws IOException A`Z!=og=  
{ ]7O)iq%  
this("",0); ^)rX27!G  
} Yb%H9A  
7S7gU\qOj  
UAnq|NJO  
public FileAccessI(String sName,long nPos) throws IOException 699z@>$}
 
{ Gbwcb
fH  
oSavedFile = new RandomAccessFile(sName,"rw"); 1 <.I2\^  
this.nPos = nPos; 
\U4O*lq  
oSavedFile.seek(nPos); 2WIL0Siwl  
} Pr{?A]dQ  
?Bq"9*q  
:7D&=n)  
public synchronized int write(byte[] b,int nStart,int nLen) jRm:9`.Q  
{ ]NNLr;p  
int n = -1; pM@|P,w {  
try{ |]RV[S3v  
oSavedFile.write(b,nStart,nLen); {0q;:
7Bt  
n = nLen;  8;4vr@EV  
} Pqo_+fL+  
catch(IOException e) Op,Ce4A  
{ bENfEOf,  
e.printStackTrace (); X |.'_6l.  
} Id *Gs>4U  
jx!)N>  
lInq=  
return n; pNcNU[c  
} $B7<1{<=W  
e7t).s)b{  
>1`FRw<  
} P1vr}J  
Vpt)?];P  
R<Ojaj=V  
/* sT[)r]`T  
**SiteInfoBean.java xoTS?7  
*/ !oLrN/-  
package NetFox; R,C)|*ef  
0J_ AX  
5znLpBX<N  
public class SiteInfoBean { }e6Ta_Z~  
n <6}  
d;Z<")  
private String sSiteURL; //Site's URL >T%Jlj3ZG  
private String sFilePath; //Saved File's Path ~cz]Rhq  
private String sFileName; //Saved File's Name Dn) =V.  
private int nSplitter; //Count of Splited Downloading File &9$0v"`H  
fa=#S  
 $Tfq9  
public SiteInfoBean() t LdBnf  
{//nSplitter的缺省值为5 a^'1o9  
//default value of nSplitter is 5 $yIcut7  
this("","","",5); VQZ3&]o  
} F8;M+
+  
TYw0#ZXo  
g^NdN46%  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) YPDc /  
{ ?1xBhKq  
sSiteURL= sURL; 3P6pQm'.f  
sFilePath = sPath; F
 71  
sFileName = sName; +uM1#-+h  
this.nSplitter = nSpiltter; ge`)sB,  
9bPQD{Qb  
Fm3-Sn|Po  
} CM>/b3nOW  
Dj
;h!8t.  
>MUwT$szs  
public String getSSiteURL() *#+d j"  
{ AU}lKq7%  
return sSiteURL; 9xB^dKM3  
} *;7&  
r62x*?/  
;Z-Cn.  
public void setSSiteURL(String value) z:^Kr"=n  
{ lN,b@;  
sSiteURL = value; Y:^~KS=Uz  
} b\7-u-   
{0lY\#qcE  
:bE ^
b  
public String getSFilePath() RecA?-0  
{ O4@Ki4f3A%  
return sFilePath; { Y|h;@j$  
} oB-&ma[ZS  
pco~Z{n  
q+x4Od3  
public void setSFilePath(String value) Y)N(uv6  
{ yrdJX  
sFilePath = value; +o?.<[>!GR  
} h.%VWsAO7  
@\i6m]\X  
RI:x`do  
public String getSFileName() 6]\F_Z41  
{ r9uY?M  
return sFileName; Gs7mO  
} Mw?nIIu(@  
C0jmjZ%w@  
uwj/]#`  
public void setSFileName(String value) wHBkaPO!  
{ a{L`C"rJ  
sFileName = value; K-)*S\<}  
} )*G3q/l1u6  
M`FsKK`  
[])M2_  
public int getNSplitter() }y
LdU|'W  
{ ;QR|v  
return nSplitter; prlnK  
} 5u:+hB  
r4gkSwy  
5dMIv<#T`  
public void setNSplitter(int nCount) %\}|&z6  
{ DHbLS3-  
nSplitter = nCount;  s+[_5n~  
} k)[}3oq  
} en=Z[ZIPO  
(iP,F]  
fm;1Iu#  
/* HLN rI0  
**Utility.java MEI]N0L3  
*/ .Ap[C? mV  
package NetFox;  c?}C{  
3! dD!'  
j5R= K*y  
public class Utility { x~$P.X7(~  
lBR6O!sBP  
Jb6rEV>  
public Utility() G 8uX[-L1  
{ J,;;`sf  
9*[!uu  
3HO4h\mp  
} S5"xb  
u4IgPCTZ+  
//线程睡眠 Y3-Tg~/~W  
public static void sleep(int nSecond) eoR@5OA&  
{ C]WVH\Pp  
try{ (*/P~$xIj  
Thread.sleep(nSecond); s$C;31k  
} 9$~D4T  
catch(Exception e) Aw4Qm2Kf  
{ m/0G=%d%k
 
e.printStackTrace (); cK(}B_D$  
} IQGIU3O  
} [dk|lkj@u\  
B6 x5E  
//日志 k5w+{iOh  
public static void log(String sMsg) -njxc{b  
{ vO]gj/SaT  
System.err.println(sMsg); R{#-IH="  
} Z
B`!@/3X  
Kw(/#C:$  
S?r:=GS  
public static void log(int sMsg) ]}ff*W  
{ b=F"  
System.err.println(sMsg); A!Ng@r  
} vD:.1,72  
} csRba;Z[  
PaMi5Pq  
YxS*im[%]  
/* S^I38gJd  
**TestMethod.java qI<*Cze  
*/ eY\tO"Hc  
package NetFox; /p<mD-:.M  
^P"
t "  
a+A/
l  
public class TestMethod { O5_[T43  
I}n"6'*  
cn<9!2a  
public TestMethod() `WWf
?g  
{ ///xx/weblogic60b2_win.exe 4yQ4lU,r  
try{ W;~^3Hz6  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); twf;{lZ(  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Kl(}s{YFn.  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]K XknEaxl  
fileFetch.start(); 0 v/+%%4}  
} JR 2v}b  
catch(Exception e){e.printStackTrace ();} x[WT)  
dXe763~<  
~i))Zc3,g\  
} m1\>v?=K  
T1n GBl\(  
*fSa8CV  
public static void main(String[] args) }9Y='+.%^  
{ ~`*:E'/5k]  
new TestMethod(); F:hJ^:BP  
} " 8;D^
 
} /Klwh1E  
点击下载更多相关资料