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http断点续传简单实现(java)

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/* jsd]7C  
**SiteFileFetch.java /t)c fFM  
*/ WXLe,7y  
package NetFox; Z(Eke  
import java.io.*; 1C0Y0{6,  
import java.net.*; 8 _4l"v p  
){+[$@9  
5@ bc(H  
public class SiteFileFetch extends Thread { $bZu^d,  
7`b lGzP_  
YgfSC}a  
SiteInfoBean siteInfoBean = null; //文件信息Bean &r'{(O8$N  
long[] nStartPos; //开始位置 rb:<N%*t  
long[] nEndPos; //结束位置 w.J%qWJq  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 |;A9A's  
long nFileLength; //文件长度 1 [Sv  
boolean bFirst = true; //是否第一次取文件 *.m{jgi1X  
boolean bStop = false; //停止标志 X~v4"|a  
File tmpFile; //文件下载的临时信息 &GdL 9!hH  
DataOutputStream output; //输出到文件的输出流 Y&vHOA  
ZjU=~)O}H  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) m<FF$pTT  
public SiteFileFetch(SiteInfoBean bean) throws IOException C9<4~IM w  
{ {q&@nm40  
siteInfoBean = bean; 81g9ZV(4  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 9?uqQ  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 7$(_j<o`  
if(tmpFile.exists ()) / <JY:1|  
{ uu}a:qrY  
bFirst = false; 2?GXkPF2;A  
read_nPos(); B/jrYT$;m  
} {]&R8?%  
else j#N(1}r=1  
{ 7{n\y l?  
nStartPos = new long[bean.getNSplitter()]; ^DBD63 N"  
nEndPos = new long[bean.getNSplitter()]; KHvIN}V5?3  
} RK?jtb=&A  
/^w"' '  
0/ut:RV0  
" Wp   
} saatU;V  
c#=&!FRe  
lZ}P{d'f.  
public void run() j7f5|^/x3  
{ !0`lu_ZN  
//获得文件长度 X$/E>I  
//分割文件 avlqDi1l  
//实例FileSplitterFetch V {p*z  
//启动FileSplitterFetch线程 21U&Ww  
//等待子线程返回 w{3ycR  
try{ 8Bq-0=E  
if(bFirst) !6lOIgn  
{ (I[s3EnhS  
nFileLength = getFileSize(); sTiYf  
if(nFileLength == -1) U<Vy>gIC  
{ "c6<zP  
System.err.println("File Length is not known!"); *\D}eBd|  
} iecWa:('  
else if(nFileLength == -2) JRq3>P  
{ E-^2"j >o  
System.err.println("File is not access!");  m;c3Z-  
} Y,'%7u  
else fTcY"A,2  
{ /N>} 4Ay  
for(int i=0;i<nStartPos.length;i++) wZQ)jo7*g  
{ 0*/kGvw`i  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ^}J<)}Q  
} (Ux [[  
for(int i=0;i<nEndPos.length-1;i++) }w#F6  
{ 6(Vhtr2( *  
nEndPos = nStartPos[i+1]; e gI&epN  
} `%Q&</X  
nEndPos[nEndPos.length-1] = nFileLength; _B3zRO  
} zd.'*Dj  
} aZ6'|S;  
`^x9(i/NE  
+p z}4M`  
//启动子线程  t!jYu<P  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Yk'm?p#~  
for(int i=0;i<nStartPos.length;i++) J1X~vQAe  
{ 0\Y1}C  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), JGis"e  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &))\2pl  
nStartPos,nEndPos,i); ^&Q< tN 7  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i'=2Y9S}  
fileSplitterFetch.start(); aBxiK[[`  
} f}iU& 3S  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >?I/;R.-  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); rEM#D]k  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", epkD*7  
nEndPos = " + nFileLength); W:vr@e6  
// fileSplitterFetch[nPos.length-1].start(); FshC )[w,  
)c+k_;t'+  
pawl|Z'Ez  
//等待子线程结束 mlB~V3M'G  
//int count = 0; id?E)Jy  
//是否结束while循环 "(f`U.  
boolean breakWhile = false; "}zt`3  
^_W40/c3  
MA* :<l  
while(!bStop) n Q-mmY>#  
{ Qnt5HSSt  
write_nPos(); Oaa"T8t  
Utility.sleep(500); w7 *V^B  
breakWhile = true; z:}nBCmLV  
/iG7MC\`  
g`[$Xi R  
for(int i=0;i<nStartPos.length;i++) cP rwW 6  
{ q7_+}"i  
if(!fileSplitterFetch.bDownOver) {v,)G)obWw  
{ [_.n$p-  
breakWhile = false; J'Sm0  
break; +TSSi em  
} !Z|($21W  
} ;dZMa]X0  
if(breakWhile) r4Q|5kT*i  
break; VteEDL/w  
eV2mMSY  
qZ+H5AG2  
//count++; Q2QY* A  
//if(count>4) ahGT4d`)9  
// siteStop(); uM S*(L_  
} *9 D!A  
DNP@A4~  
DQ80B)<O  
System.err.println("文件下载结束!"); 7x k|+!  
} ^+/kr/  
catch(Exception e){e.printStackTrace ();} e.vtEQV9  
} $NG++N  
NX,-;v  
s([dGD$i  
//获得文件长度 L:R<e#kgS  
public long getFileSize() ^3~e/PKM  
{ ,hRN\Kt)p  
int nFileLength = -1; )jDJMi_[  
try{ z&}-8JykH  
URL url = new URL(siteInfoBean.getSSiteURL()); Im?LIgt$  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n}nEcXb  
httpConnection.setRequestProperty("User-Agent","NetFox"); VaLs`q&3>  
.*5Z"Q['G  
Es4qPB`g.  
int responseCode=httpConnection.getResponseCode(); HdX2YPYn;  
if(responseCode>=400) E>uVofhml  
{ #R&H &1  
processErrorCode(responseCode); \'v(Xp6  
return -2; //-2 represent access is error Ak BMwV  
} z`3( ,V  
Wf26  
QlZ@ To  
String sHeader; )"<8K}%!  
@N.jB#nEb  
ftbpqp'  
for(int i=1;;i++) ~Y!kB:D5;~  
{ &^.57]  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); EqB)sK/3  
//Utility.log(in.readLine());  zGlZ!t:  
sHeader=httpConnection.getHeaderFieldKey(i); c j$6  
if(sHeader!=null) 9Kv|>#zff  
{ qUJ aeQ  
if(sHeader.equals("Content-Length")) Gc,_v3\  
{ 8|g<X1H{M  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,xi({{L*  
break; sM2MLh'D  
} X$n(-65  
} 4=<*Vd`p  
else <[~,uR7  
break; F7}-!  
} a2@c%i  
} au@a8MP  
catch(IOException e){e.printStackTrace ();} Y3U9:VB  
catch(Exception e){e.printStackTrace ();} hpbf&S4  
Ctu?o+^;z  
{8RFK4! V@  
Utility.log(nFileLength); V-yUJ#f8[  
Kq6jw/T  
GZ#aj|  
return nFileLength; E8[T   
} *ZCn8m:-+  
_8?o'<!8?^  
/F/;G*n  
//保存下载信息(文件指针位置) _=XX~^I,  
private void write_nPos() ^"8wUsP  
{ 0#p/A^\#7M  
try{ 5]Ajf;W\  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5g5'@vMN  
output.writeInt(nStartPos.length); dl]#  
for(int i=0;i<nStartPos.length;i++) Q / x8 #X  
{ rS XzBi{  
// output.writeLong(nPos); 8MwK.H[U  
output.writeLong(fileSplitterFetch.nStartPos); ( )T[$.(  
output.writeLong(fileSplitterFetch.nEndPos); u{H?4|'(  
} BRRj$)u  
output.close(); R!\EK H  
} kLSrj\6I[  
catch(IOException e){e.printStackTrace ();} n$L51#'  
catch(Exception e){e.printStackTrace ();} #\rwLpC1u  
} +K",^6%1  
)u:Q) %$t  
g{k1&|  
//读取保存的下载信息(文件指针位置) tfO#vw,@  
private void read_nPos() %|W.^q  
{ A#wEuX=[  
try{ =3xE:  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )(M7lq.e7  
int nCount = input.readInt(); v-j3bB  
nStartPos = new long[nCount]; YvL?j  
nEndPos = new long[nCount]; 6aft$A}XnD  
for(int i=0;i<nStartPos.length;i++) knp>m,w  
{ )$GIN/i  
nStartPos = input.readLong(); [IZM.r`Z  
nEndPos = input.readLong(); X@N$Z{  
} I,@r5tK o  
input.close(); 2 !1.E5.I  
} vsB*rP=  
catch(IOException e){e.printStackTrace ();} XKOUQc4!R  
catch(Exception e){e.printStackTrace ();} SuBeNA[&  
} XUMX*  
oih5B<&f#  
zk_Eb?mhwV  
private void processErrorCode(int nErrorCode) ~`8hwR1&z  
{ -;(Q1)&  
System.err.println("Error Code : " + nErrorCode); +!t}  
} Nil}js27  
>c8GW >\N  
4Aes#{R3v  
//停止文件下载 -[7O7'  
public void siteStop() RSfM]w}Hq#  
{ B0}~G(t(  
bStop = true; >B -q@D  
for(int i=0;i<nStartPos.length;i++) 's?Ai2=#  
fileSplitterFetch.splitterStop(); QWnndI_4p  
<~emx'F|  
@ T ;L$x  
} 9W7#u}Z  
} @`"AHt  
//负责部分文件的抓取 w?vVVA  
**FileSplitterFetch.java ihe(F7\U  
*/ *O$CaAr\s  
package NetFox; q z&+=d@  
,<,:8B  
F!!N9VIC  
import java.io.*; 4'pS*v  
import java.net.*; 10[Jl5+t  
OKOu`Hz@  
-4#2/GXNO  
public class FileSplitterFetch extends Thread {  l]!9$  
h[tix:  
`b5 @}',  
String sURL; //File URL i8X`HbmN  
long nStartPos; //File Snippet Start Position 0[A9b,MMVO  
long nEndPos; //File Snippet End Position SjEAuRDvUz  
int nThreadID; //Thread's ID B6P|Z%E;D6  
boolean bDownOver = false; //Downing is over er.L7  
boolean bStop = false; //Stop identical F51.N{'  
FileAccessI fileAccessI = null; //File Access interface `\Ku]6J]5  
#.B"q:CW*P  
pI[ZBoR~  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException R\Z: n*  
{ ~|Y>:M+0Z  
this.sURL = sURL; u'A#%}3  
this.nStartPos = nStart; ~`#-d ^s:  
this.nEndPos = nEnd; %bXtKhg5eJ  
nThreadID = id; 0o&MB Dp  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 zW |=2oX2  
} ^}yg%+  
+ A_J1iJ<  
xvLn'8H.  
public void run() $gle8Z-  
{ 'Yy&G\S  
while(nStartPos < nEndPos && !bStop) #1-xw~_  
{ ~q0*"\Ff  
^,Ydr~|T  
ITuq/qts]A  
try{ ewsKH\#  
URL url = new URL(sURL); TB6m0qX(  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oSb, :^Wl  
httpConnection.setRequestProperty("User-Agent","NetFox"); y? (2U6c  
String sProperty = "bytes="+nStartPos+"-"; 6X g]/FD  
httpConnection.setRequestProperty("RANGE",sProperty); bucR">_p  
Utility.log(sProperty); 1[nG}  
uUR~&8ERX  
{.e=qQ%P5)  
InputStream input = httpConnection.getInputStream(); LS>G4 ]  
//logResponseHead(httpConnection); 5wtTP ;P  
JHn*->m  
:bU(S<%M  
byte[] b = new byte[1024]; bJr[I  
int nRead; Jhkvd<L8`m  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) iGXI6`F"  
{ 7iC *Pr  
nStartPos += fileAccessI.write(b,0,nRead); ?0*8R K  
//if(nThreadID == 1) _,h@:Xij  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kQdt}o])  
} ["<nq`~  
omZO+=8Q  
vy@rQC %9  
Utility.log("Thread " + nThreadID + " is over!"); F-Z%6O,2  
bDownOver = true; 8Q`WB0E<|  
//nPos = fileAccessI.write (b,0,nRead); $e%2t^ i.g  
} d=.2@Ry  
catch(Exception e){e.printStackTrace ();} Q<tu)Qo  
} &FdWFt=X  
} =x#FbvV  
[ANuBNF  
"LhUxnll  
//打印回应的头信息 VUU]Pu &  
public void logResponseHead(HttpURLConnection con) > Vb@[  
{ yWPIIWHx!  
for(int i=1;;i++) tEd.'D8 s  
{ qgt[~i*  
String header=con.getHeaderFieldKey(i); z:Sigo_z[  
if(header!=null) Kz8:UG(  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); iSRpfU  
Utility.log(header+" : "+con.getHeaderField(header)); UQ Co}vM  
else fr6^nDY  
break; wHjLd$ +o  
} ]T! }XXK  
} *TW=/+j  
Q3W#`6jpF  
2U kK0ls  
public void splitterStop() 7"X>?@  
{ /{2*WI;  
bStop = true; Id'RL2Kq*&  
} .@ C{3$,VG  
=`n]/L"Q  
t,)N('m}=  
} I&9S;I$  
2],_^XBvB  
tL SN`6[:  
/* _:n b&B  
**FileAccess.java Gnm4gF!BI  
*//文件访问(定位,写) k#TYKft  
package NetFox; hlZ@Dq%f  
import java.io.*; :m=m}3/:  
c47")2/yO  
Dz=k7zRg"  
public class FileAccessI implements Serializable{ G}@#u9  
uNbH\qd=  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 h5z)Lc^  
RandomAccessFile oSavedFile; ulHn#)  
long nPos; 0XwHP{XaO  
7DW]JK l  
V5"CSMe  
public FileAccessI() throws IOException a>4uiFiv  
{ M/PFPJ >`  
this("",0); SDG-~(Y  
} ?zJpD8e  
j;yf8Nf  
fHrt+_Zn|  
public FileAccessI(String sName,long nPos) throws IOException -37a.  
{ (LvS :?T}  
oSavedFile = new RandomAccessFile(sName,"rw"); /z7VNkD  
this.nPos = nPos; )o1eWL}  
oSavedFile.seek(nPos); Q0?\]2eet9  
} +^aFs S  
3T\l]? z  
eC DIwB28  
public synchronized int write(byte[] b,int nStart,int nLen) vP%tk s+.  
{ zHWSE7!  
int n = -1; ,?UM;^  
try{ |as!Ui/J/  
oSavedFile.write(b,nStart,nLen); Z.L?1V8Q1  
n = nLen; yAT^VRbv  
} }F6<w{|  
catch(IOException e) uxn)R#?  
{ ubMOD<  
e.printStackTrace (); ;^ wd_  
} .@)mxC:\K9  
seFGJfN\?f  
xVB;s.'!  
return n; I:&/`K4,x,  
} sML=5=otx  
kB:Uu }(=N  
P`4]-5gE  
} 6\7nc FO3  
\mM<\-'p  
h!@|RW&}qX  
/* s1Ok|31|  
**SiteInfoBean.java s>_V   
*/ n>3U_yt6b  
package NetFox; uf<@ruN  
<oKGD50#  
5[l8y ,  
public class SiteInfoBean { -hcS]~F  
5V[oE\B  
 ~fl@ 2  
private String sSiteURL; //Site's URL %)jxW{  
private String sFilePath; //Saved File's Path ?PA$Ur21lw  
private String sFileName; //Saved File's Name 7`vEe 'qz  
private int nSplitter; //Count of Splited Downloading File z't? ?6  
[%~ :@m  
{_N,=DQ!  
public SiteInfoBean() |@?%Ct  
{//nSplitter的缺省值为5 M}:=zcZ l  
//default value of nSplitter is 5 r;9 r!$d  
this("","","",5); \]Kh[z0"  
} rD?L  
q/3ziVd7p  
3<=,1 cU  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) c0c|z Ym  
{ 7g=2Z[o  
sSiteURL= sURL; N#V.1<Y  
sFilePath = sPath; eAUcv`[#p  
sFileName = sName; O1%pxX'`S  
this.nSplitter = nSpiltter; kp?w2+rz  
<9ig?{'  
 [=O/1T  
} bn 6WjJ~Z+  
NW~z&8L  
Z UKf`m[  
public String getSSiteURL() 4%WzIzRb  
{ Qjx?ri//  
return sSiteURL; }nt* [:%  
} _AV1WS;^^8  
MRU7W4W-~/  
7\_o.(g#-  
public void setSSiteURL(String value) I8oo~2Q w  
{ }:: S 0l  
sSiteURL = value; VxP&j0M>  
} wB'zuPAK6  
8x`.26p  
%h1N3\y9i(  
public String getSFilePath() I%|>2}-_U  
{ pEECHk  
return sFilePath; Y_`-9'&  
} ' |-JWH  
L lqM c  
XC{eX&,2x  
public void setSFilePath(String value) .4. b*5  
{ 9nu3+.&P  
sFilePath = value; f7Ul(D:j\  
} "CiTa>x  
3_JCU05H}  
0$r^C6}f  
public String getSFileName() t1E[uu,V8  
{ rD>*j~_+P  
return sFileName; =PGs{?+&O  
} 4Llo`K4  
L(GjZAP  
O25lLNmO  
public void setSFileName(String value) d1[ZHio2c?  
{ x8GJY~:SW  
sFileName = value; Y8flrM2CwG  
} SkU9ON   
tTd\|  
+{sqcr1G  
public int getNSplitter() mf'V)  
{ G "P4-  
return nSplitter; G[jW<'f  
} Z"unF9`"1  
;c$J=h]  
z3?o|A}/W  
public void setNSplitter(int nCount) 1}~(Yj@f%  
{ .F+@B\A<  
nSplitter = nCount; FLEo*9u>b  
} @JdZ5Q  
} jt+iv*2N>  
a&vY!vx 3  
S*yjee<@  
/* v%Wx4v@%SE  
**Utility.java ,@5I:X!rR  
*/ JU&+c6>  
package NetFox; Z0l+1iMx  
nB .G  
1'? 4m0W1  
public class Utility { Y`?-VaY  
1^gl}^|B  
8V~vXnkM  
public Utility() bJs9X/E  
{ DK}"b}Fvq  
}f2r!7:x  
!>:?rSg*  
} y+7PwBo%e  
NVRLrJWpp  
//线程睡眠 av~5l4YL  
public static void sleep(int nSecond) |fo0  
{ Jec'`,Y  
try{ K$d$m <  
Thread.sleep(nSecond); J`2"KzR0w"  
} [n}T|<  
catch(Exception e) &\_iOw8  
{ 64 5z#_}C$  
e.printStackTrace (); f7}*X|_Y  
} CD8}I85 K  
} }}<z/zN&^  
aM;W$1h  
//日志 4f<$4d^md  
public static void log(String sMsg) =z8f]/k*>  
{ +]Y,q w  
System.err.println(sMsg); 9+pmS#>_  
} {^N[("`  
QPq7R  
0Zg%+)iy@  
public static void log(int sMsg) ZWS`\M  
{ N 8-oY$*  
System.err.println(sMsg); MuSUKBhM  
} /Ju;MeE9  
} PsZ >P|e1  
2;?I>~  
e zOj+vz  
/* J4\qEO  
**TestMethod.java b Ax?&$  
*/ Hik3wPnp  
package NetFox; }C|dyyr  
l(Q?rwI8Y  
-ne Kuj  
public class TestMethod { M4W5f#C5Ee  
p l&Muv  
0c#/hFn  
public TestMethod() ,tg0L$qC  
{ ///xx/weblogic60b2_win.exe CH<E,Z C1T  
try{ 42qYg(tZ  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Z R'H \Z  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Q6r7.pk"SU  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2j&AiD  
fileFetch.start(); ]H1I,`=@  
} T|6a("RL  
catch(Exception e){e.printStackTrace ();} )=etG  
P$-X)c$&  
Q0ON9gqqv  
} VzKW:St  
y? co|  
3F<VH  
public static void main(String[] args) %p 0xM  
{ Y"wUt &  
new TestMethod(); X ' "SVO.  
} ze]h..,]K  
} 5O6hxcMjT  
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