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http断点续传简单实现(java)

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/* p!~1~q6  
**SiteFileFetch.java }zS5o [OE  
*/ dC8}Ttc}  
package NetFox; ";7xE#jRk  
import java.io.*; O_ZYm{T[7  
import java.net.*; Z:<an+v|5  
x@QNMK.7  
w3"L5;oH  
public class SiteFileFetch extends Thread { P[-do  
V@T(%6<|  
F~qZIggD  
SiteInfoBean siteInfoBean = null; //文件信息Bean "/RMIS K[;  
long[] nStartPos; //开始位置 /:Gy .  
long[] nEndPos; //结束位置 5y 5Dn!`  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 VH~YwO!x  
long nFileLength; //文件长度 79c M _O  
boolean bFirst = true; //是否第一次取文件 nT}Wx/aT  
boolean bStop = false; //停止标志 b>8TH-1t~  
File tmpFile; //文件下载的临时信息 ~@Q ]@8Tv\  
DataOutputStream output; //输出到文件的输出流 Vs{\ YfF  
n}[S  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) `Fo/RZOW  
public SiteFileFetch(SiteInfoBean bean) throws IOException '2i !RT-  
{ H8[A*uYL  
siteInfoBean = bean; )qw;KG0F  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ypG*41  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ~Gz9pBv1  
if(tmpFile.exists ()) d"miPR  
{ @y~kQ5k  
bFirst = false; f+hHc8g  
read_nPos(); "O0xh_Nr  
} ls&H oJ7  
else M-@X&b m,S  
{ A9 g%>  
nStartPos = new long[bean.getNSplitter()]; mICEJ\`x  
nEndPos = new long[bean.getNSplitter()]; Xpn\TD<_I  
} ^d{5GK'  
j}",+H v  
hL6;n*S=  
q)Nw$dW<  
} [RN]?,  
}.E^_`  
TUC)S&bC  
public void run() -5 PVWL\  
{ wB[f%mHs  
//获得文件长度 oC49c~`8  
//分割文件 ) c\Y!vS  
//实例FileSplitterFetch pKy4***I3  
//启动FileSplitterFetch线程 ls:oC},p*  
//等待子线程返回 gee~>l  
try{ mc8Q2eQat}  
if(bFirst) =hFY-~U  
{ <MkvlLu((o  
nFileLength = getFileSize(); 0>7Ij7\[8  
if(nFileLength == -1) bA#9'Qu^j  
{ 4xmJQ>/  
System.err.println("File Length is not known!"); gh ?[x.U  
} G Ixs>E'X  
else if(nFileLength == -2) J'|=J   
{ Y06^M?}  
System.err.println("File is not access!"); S\8v)|Pr  
} pN5kcvQ  
else 7GsKD=bl]  
{ .waw=C  
for(int i=0;i<nStartPos.length;i++) Vn sV&cx  
{ ;un@E:  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); zvdut ,6<  
} I@ue eDY  
for(int i=0;i<nEndPos.length-1;i++) ^_Hf}8H7]  
{ F6[F~^9D  
nEndPos = nStartPos[i+1]; pvyEs|f=%  
} F/5G~17  
nEndPos[nEndPos.length-1] = nFileLength; \(j*K6#  
} $YEm(:v$  
} w/nohZF6H  
x5Lbe5/P  
-t|/g5.w_  
//启动子线程 r3g^ 0|)  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; M.mn9kw`  
for(int i=0;i<nStartPos.length;i++) C(G.yd  
{ I!Z`'1"  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5;0w({1l  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), BeVDTk :  
nStartPos,nEndPos,i); JK =A=  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xyGwYv>*KO  
fileSplitterFetch.start(); ?/3wO/7[  
} ?^%[*OCCC!  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R<&Euph  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Z2$_9.  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", UGO;5!  
nEndPos = " + nFileLength); xO )c23Z)]  
// fileSplitterFetch[nPos.length-1].start(); M co:eE  
 lrv-[}}  
]H n:c'aT  
//等待子线程结束 larv6ncV  
//int count = 0; _R ii19k  
//是否结束while循环 hUlRtt  
boolean breakWhile = false; ES+ CAwqf  
.A< HM}   
['}|#3*w  
while(!bStop) _h-agn4[i  
{ #Zm`*s`  
write_nPos(); Ww-x+U\l  
Utility.sleep(500);  ydzsJ+dx  
breakWhile = true; *m"9F'(Sd  
hH1Q:}a  
KY  
for(int i=0;i<nStartPos.length;i++) k={D!4kKz  
{ &gXL{cK'%  
if(!fileSplitterFetch.bDownOver) plWNuEW  
{ \|Af26  
breakWhile = false; F|F0#HC ?  
break; W/2y; @  
} MF"*xr v  
} .:j{d}p}  
if(breakWhile) Z3TCi7,m  
break; w PR Ns9^  
fYP,V0P  
NRx 7S 9W  
//count++; @o0HDS  
//if(count>4) \7LL neq  
// siteStop(); Jq` Dvz  
} ~%*l>GkP*  
jI8`trD  
vX }iA|`#  
System.err.println("文件下载结束!"); \ZcI{t'a  
} j>JBZ#g  
catch(Exception e){e.printStackTrace ();} ~},H+A!?  
} */K[B(G  
@JlT*:Dz  
T/|!^qLF  
//获得文件长度 (>0`e8v!  
public long getFileSize() VzSkqWF/"  
{ Zl3l=x h  
int nFileLength = -1; {1)bLG|$  
try{ a^&"gGg  
URL url = new URL(siteInfoBean.getSSiteURL()); zdJPMNHg  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1^$hbRq  
httpConnection.setRequestProperty("User-Agent","NetFox"); @-)S*+8  
: _Y^o  
_(f@b1O~  
int responseCode=httpConnection.getResponseCode(); <. Tllk@r)  
if(responseCode>=400) -J63'bb7oi  
{ &pI\VIx ?  
processErrorCode(responseCode); ;*qXjv& K  
return -2; //-2 represent access is error mdL T7  
} ,$Fh^KNo]  
'~ b  
Qf0P"s`  
String sHeader; <IR@/b!,  
x%X3FbF]  
?5">50  
for(int i=1;;i++) EO+Ix7w  
{ e[x,@P`  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1<@lM8&.kO  
//Utility.log(in.readLine()); ;L87 %P(.  
sHeader=httpConnection.getHeaderFieldKey(i); 60~*$`  
if(sHeader!=null) MkVv5C  
{ Q']'KU.  
if(sHeader.equals("Content-Length")) '(r?($s  
{ &S.p%Qe"  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); KD#zsL)3  
break; =X'EDw  
} j\KOKvY)  
} <8%+-[(  
else ~jKIuO/  
break; A["6dbvv  
} !pe[H*Cy  
} Y]R=z*i%  
catch(IOException e){e.printStackTrace ();} b^i$2$9_  
catch(Exception e){e.printStackTrace ();} ? }^ y6  
t`&mszd~T  
d+P<ce2 G  
Utility.log(nFileLength); .))k  
"j`T'%EV  
M&zB&Ia"'  
return nFileLength; hDJ+Rk@  
} i]zh8|">  
U#Kw+slM  
LVP6vs  
//保存下载信息(文件指针位置) hBZh0x y  
private void write_nPos() l+(B~v  
{ o}36bi{  
try{ QncjSaEE  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9%k4Ic%P  
output.writeInt(nStartPos.length); -[=@'N P  
for(int i=0;i<nStartPos.length;i++) 31g1zdT!  
{ JKYtBXOl  
// output.writeLong(nPos); HE4S%#bH>  
output.writeLong(fileSplitterFetch.nStartPos); ctgH/SU  
output.writeLong(fileSplitterFetch.nEndPos); U GOe(JB  
} muK)Y w[#N  
output.close(); qyE*?73W  
} y#ON=8l  
catch(IOException e){e.printStackTrace ();} ' z^v}~  
catch(Exception e){e.printStackTrace ();} MmfshnTN  
} VF-[O  
tr 8Q{  
q<g!bW%  
//读取保存的下载信息(文件指针位置)  Mv%B#J  
private void read_nPos() ='/#G0W  
{ 8r.MODZG/  
try{ iQh:y:Jo1&  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9zehwl]~  
int nCount = input.readInt(); 3z 5"Ckzb  
nStartPos = new long[nCount]; ]_ y;Igaj  
nEndPos = new long[nCount]; :d~&Dt<c  
for(int i=0;i<nStartPos.length;i++) G)5Uiu:^X  
{ K8iQ?  
nStartPos = input.readLong(); uvD*]zX  
nEndPos = input.readLong(); FZ% WD@=  
} j]9,yi  
input.close(); J:;nN-\j  
} zt )WX9  
catch(IOException e){e.printStackTrace ();} 6:TA8w|  
catch(Exception e){e.printStackTrace ();} SMm$4h R  
} Sj'.)nz>  
'Ya-;5Y]  
"FfP&lF/  
private void processErrorCode(int nErrorCode) P6ugbq[x#e  
{ 0[OlJMVf  
System.err.println("Error Code : " + nErrorCode); sr.!EQ]  
} H,1I z@W1  
Uv3Fe%>  
*5'l"YQ@1  
//停止文件下载 kh*td(pfP9  
public void siteStop() y=WCR*N  
{ SL% Ec%9Y  
bStop = true; FE?^}VH  
for(int i=0;i<nStartPos.length;i++) g>Kh? (  
fileSplitterFetch.splitterStop(); {$-\)K  
^$\#aTyFK  
K}Pi"Le@W  
} N%8aLD  
} \E:l E/y  
//负责部分文件的抓取 |Q~5TL>b  
**FileSplitterFetch.java WPNvZg9*c  
*/ ![@\p5-e  
package NetFox; xXc3#n  
A&;Pt/#'  
bMF`KRP2  
import java.io.*; !p"Ijz5  
import java.net.*; TYr"yZ([  
Ja6PX P]'  
9ioV R  
public class FileSplitterFetch extends Thread { S QVyCxcX_  
B6a   
+aIy':P  
String sURL; //File URL n<>/X_m  
long nStartPos; //File Snippet Start Position O0#9D'{  
long nEndPos; //File Snippet End Position 5oI gxy  
int nThreadID; //Thread's ID naKB2y]l  
boolean bDownOver = false; //Downing is over ZvO,1B  
boolean bStop = false; //Stop identical o.H(&ex|  
FileAccessI fileAccessI = null; //File Access interface N,NEg4 q[  
o8lwwM*  
Nl`8Kcv  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException rN^P//  
{ T8rf+B/.L  
this.sURL = sURL; /SZg34%  
this.nStartPos = nStart; %phv<AW  
this.nEndPos = nEnd; Fs EPM"&?h  
nThreadID = id; b}#ay2AR  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^iq$zHbc0u  
} {n>W8sN<  
GiN\@F!  
#<|q4a{8  
public void run() FO5'<G-  
{ Hh1OD?N)  
while(nStartPos < nEndPos && !bStop) Pa !r*(M)C  
{  Z,osdF  
;eeu 9_$  
mT2Fn8yC1  
try{ n7 S~n k  
URL url = new URL(sURL); c);(+b  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x p#+{}  
httpConnection.setRequestProperty("User-Agent","NetFox"); wN ![SM/+  
String sProperty = "bytes="+nStartPos+"-"; yXx}'=&!0  
httpConnection.setRequestProperty("RANGE",sProperty); ES#K'Lf  
Utility.log(sProperty); <2a7>\74E0  
to  
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InputStream input = httpConnection.getInputStream(); 9H<6k*  
//logResponseHead(httpConnection); &v^LxLt+s  
vK?{Z^J][  
zF[>K4  
byte[] b = new byte[1024]; 3Yd)Fm  
int nRead; _YH)E^If  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5!PU+9Kh  
{ e>kw>%3bl9  
nStartPos += fileAccessI.write(b,0,nRead); t3 q0|S  
//if(nThreadID == 1) e ga< {t  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &r;4$7  
} m"!!)  
;Vad| -  
"yI)F~A  
Utility.log("Thread " + nThreadID + " is over!"); 46dh@&U  
bDownOver = true; `q 4%  
//nPos = fileAccessI.write (b,0,nRead); ba3_5 5]  
} b7/1 ]  
catch(Exception e){e.printStackTrace ();} uSs~P%@6|  
} .jh uC#x{/  
} +x!V;H(  
`bGAc&,&  
) tGC&l+?/  
//打印回应的头信息 otXB:a  
public void logResponseHead(HttpURLConnection con) }Jgz#d  
{ j`\}xDg  
for(int i=1;;i++) cvbv\G'aT  
{ u8*Uia*vwH  
String header=con.getHeaderFieldKey(i); j+n1k^jC  
if(header!=null) j0k"iv  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); '$M=H.  
Utility.log(header+" : "+con.getHeaderField(header)); Rp)82- .  
else 33\{S$p  
break; `?Wak =]g  
} d;ElqRC&  
} Y XH9Q@Gn  
#Vanw!  
=@m|g )  
public void splitterStop() X+{4,?04+  
{ S*:b\{[f>  
bStop = true; X;T(?,,  
} [t /hjm"$  
#5T+P8  
S >uzW #  
} -lyT8qZ:(  
ocy fU=}X  
:?{ **&=  
/* C}+w<  
**FileAccess.java O~B iqm  
*//文件访问(定位,写) J;+iW*E:  
package NetFox; r}9qK%C G.  
import java.io.*; :a}hd^;[%8  
jR\T\r4  
cp2e,%o  
public class FileAccessI implements Serializable{ 9xC,i )  
&-9wU Z  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 w@ 4q D  
RandomAccessFile oSavedFile; H__9%p#  
long nPos; ;]MHU/  
m"~$JA u  
cxrUk$f  
public FileAccessI() throws IOException }V?SedsY  
{ j|KZ HH%dc  
this("",0); |Z$heYP:w  
} mT>56\63  
7Rk eV  
kh 1 7  
public FileAccessI(String sName,long nPos) throws IOException *8fnxWR   
{ #5N#^#r"  
oSavedFile = new RandomAccessFile(sName,"rw"); 93[c^sc9*a  
this.nPos = nPos; bJ]g2C7`36  
oSavedFile.seek(nPos); Ej ip%m  
} l[l('-f  
f$NudG!S  
G{i}z^n  
public synchronized int write(byte[] b,int nStart,int nLen) !t{3IE  
{ 6?Rm>+2>v  
int n = -1; d /jO~+jP  
try{ M SoLx' <  
oSavedFile.write(b,nStart,nLen); "44VvpQC  
n = nLen; Ja| ! fT  
} }?^5\otu  
catch(IOException e) T c4N\Cy  
{ { o=4(RC  
e.printStackTrace (); Z[yQKy  
} hUcG3IOBf  
LXG,IG  
S`BLwnU`#  
return n; ^UZEdR;  
} <K%qaf  
z"u4t.KpL  
9Y- Sqk+  
} AiykIER/  
^TJn&k  
K~5QL/=1  
/* F"#bCnS  
**SiteInfoBean.java G\?fWqx  
*/ b!J21cg<L  
package NetFox; z[B*sbS  
AKC';J  
G,e>dp_cPu  
public class SiteInfoBean { FylL7n  
'xm_oGWE  
~EG`[cv  
private String sSiteURL; //Site's URL IExo#\0'6  
private String sFilePath; //Saved File's Path <->Nex  
private String sFileName; //Saved File's Name |G~LJsXW!v  
private int nSplitter; //Count of Splited Downloading File )d!,,o  
1hw1AJ}(F  
Wp`wIe6  
public SiteInfoBean() 4pq@o  
{//nSplitter的缺省值为5 acz8 H 0cS  
//default value of nSplitter is 5 ,di'279|  
this("","","",5); 0'wB':v  
} Mdsn"Y V  
?D]4*qsIlu  
X}Bo[YoY$  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) S H2|xn  
{ uIvy1h9m  
sSiteURL= sURL; BoE;,s>]NW  
sFilePath = sPath;  AC@WhL  
sFileName = sName; T3,"g=  
this.nSplitter = nSpiltter; n#[-1 (P  
G.OAzA13!t  
uo;aC$US  
} 3JVENn9  
^I=c]D]);  
hqIYo .<  
public String getSSiteURL() ^AkVmsv;;  
{ Y u\<  
return sSiteURL; YjN2 ,Xi  
} ifTMoC%  
+b"RZ:tKp  
FtXd6)_S  
public void setSSiteURL(String value) SIv8EMGo  
{ k nrR%e;  
sSiteURL = value; .}n,  
} 47>IT  
np,L39:sf  
z/6/   
public String getSFilePath() GxE"q-G  
{ g^ZsV:D  
return sFilePath; {j i;~9'Q  
} B?`n@/  
MF:]J  
:9un6A9JS  
public void setSFilePath(String value) Y^80@MJ  
{ [ lZo'o  
sFilePath = value; wv0d"PKTS  
} k~f3~-"  
4+%;eY.A  
\?uaHX`1  
public String getSFileName() ,CqJ ((  
{ e=K2]Y Q{  
return sFileName; R\k= CoJJ  
} par| j]  
GyI(1O AW  
v Yt-Nx  
public void setSFileName(String value) (qd$wv^ h  
{ AffVah2o:  
sFileName = value; EQZu-S`kv  
} @V{s'V   
xxxM  
<cu? g  
public int getNSplitter() VK\ Bjru9  
{ UB[tYZ  
return nSplitter; Hik8u!#P  
} @y:mj \J9  
'@enl]J  
b]S4\BBT  
public void setNSplitter(int nCount) *:t]|$;E\  
{ ZqKUz5M4  
nSplitter = nCount; 8B ZTHlUB  
} 0l-m:6  
} N)'oX3?x  
Mda~@)7$  
0CXh|AU  
/* 7oY}=281  
**Utility.java xK4b(KJj  
*/ |lH~nU.*  
package NetFox; Z}bUvr XP  
tln*Baq  
VYw vT0  
public class Utility { BM bT:)%  
Dw}8ci'  
(ov=D7>t0  
public Utility() A:Y]<jt  
{ 0Yz &aH  
uv*OiB"  
$47cKit|k:  
} #6g-{OBv  
v~-z["=}!  
//线程睡眠 'Y23U7 n0B  
public static void sleep(int nSecond) l:NEK`>i  
{ KQsS)ju  
try{ U" eP>HHp  
Thread.sleep(nSecond); aYQ!`mS::M  
} 3md yY\+&  
catch(Exception e) G=4Da~<ij  
{ 3UeG>5R  
e.printStackTrace (); uS :3Yo  
} ) *:<3g!  
} YpQ/ )fSEV  
zo66=vE!  
//日志 ?_9cFo59:  
public static void log(String sMsg) #5HJW[9  
{ x#yL&+'?Mj  
System.err.println(sMsg); CL/8p;  
} EgIFi{q=0  
9ls<Y  
?! dp0<  
public static void log(int sMsg) ^T\JFzV  
{ kE QT[Lo  
System.err.println(sMsg); 'qBg^c  
} 4)Y=)#=  
} "El$Sat`  
vG WX=O  
)_!t9gn*wr  
/* TL@_m^SM  
**TestMethod.java ?}^e,.M0?s  
*/ bG nBV7b  
package NetFox; Eugt~j3  
-)@DH;[tb  
*=}$@O S  
public class TestMethod { ~V3pj('/)'  
6 )eO%M`  
Uxx=$&#  
public TestMethod() Ty\&ARjb 8  
{ ///xx/weblogic60b2_win.exe c>d+q9M  
try{ {>>ozB.  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >L#&L ?#  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); pc}Q_~e  
SiteFileFetch fileFetch = new SiteFileFetch(bean); PIP2(-{ai  
fileFetch.start(); VR5$[-E3  
} {/12.y=)~  
catch(Exception e){e.printStackTrace ();} # 4`*`)%  
Lu}oC2  
7~TE=t  
}  ~d_Z?Z  
n5"rSgUtE  
69(z[opW  
public static void main(String[] args) Y cE:KRy  
{ {c|nIwdB  
new TestMethod(); P:t|'t  
} %b'ic  
} Y[Us"K`  
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