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http断点续传简单实现(java)

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/* />uE)R$  
**SiteFileFetch.java Nr}O6IJ>Sg  
*/ I,"q:QS+  
package NetFox; ] VEc9?  
import java.io.*; 4q?R3 \e;  
import java.net.*; ?kRx;S+  
tOZ-]>U  
P)~olrf  
public class SiteFileFetch extends Thread { sn Ou  
O&#>i]*V  
b?<@  
SiteInfoBean siteInfoBean = null; //文件信息Bean f3s4aARP  
long[] nStartPos; //开始位置 jaIcIc=Pf  
long[] nEndPos; //结束位置 aCi)icn$  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 mR|']^!SE  
long nFileLength; //文件长度 &x4*YM h  
boolean bFirst = true; //是否第一次取文件 $7-S\sDr  
boolean bStop = false; //停止标志 - /cf3  
File tmpFile; //文件下载的临时信息 fp`m>} -  
DataOutputStream output; //输出到文件的输出流 n?S)H=  
R*lq.7   
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) K M[&WT  
public SiteFileFetch(SiteInfoBean bean) throws IOException a/rQ@c>  
{ DcC|oU[  
siteInfoBean = bean; d7uS[tKqg  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); #Fgybokm  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 2Ky|+s[`[  
if(tmpFile.exists ()) rT[b ^l}  
{ =B`=f,,#3  
bFirst = false; P057]cAat<  
read_nPos(); ;y)3/46S  
} <-gGm=R_$  
else V0*MY{x#S  
{ KI].T+I  
nStartPos = new long[bean.getNSplitter()]; !Q}Bz*Y  
nEndPos = new long[bean.getNSplitter()]; +:/.\3v71  
} P%d3fFzK  
WDr=+=Zj  
{cjp8W8hS  
?B`c <H"  
} .3wx}!:*|  
Ci[Ja#p7$h  
! GtF%V  
public void run() -I z,vd  
{ TxKNDu  
//获得文件长度 *ozXilO  
//分割文件 }h|HT  
//实例FileSplitterFetch .eCUvX`$  
//启动FileSplitterFetch线程 9niffq)h  
//等待子线程返回 tiR i_  
try{ J/rF4=j%xy  
if(bFirst) <"S`ZOn  
{ j9}.U \  
nFileLength = getFileSize(); BFqM6_/J  
if(nFileLength == -1) 61sEeM  
{ /N")uuv  
System.err.println("File Length is not known!"); @HY P_hR  
} kk OjAp{<t  
else if(nFileLength == -2) ;g?o~ev 8  
{ x4`|[  
System.err.println("File is not access!"); k`\L-*:Ji  
} +xU=7chA  
else 7c<_j55(  
{ &Gm3  
for(int i=0;i<nStartPos.length;i++) K]^Jl0  
{ XAB/S8e  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 7{VN27Fa_  
} _Om5w p=:  
for(int i=0;i<nEndPos.length-1;i++) R-2Aby ts2  
{ d7Z$/ $  
nEndPos = nStartPos[i+1]; I]Z"?T  
} 2Y;iqR  
nEndPos[nEndPos.length-1] = nFileLength; a!&m\+?  
} |T*t3}  
} 3g0v,7,Zv  
YdYaLTz  
qy-Hv6oof  
//启动子线程 %4/X;w\3  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g}BS:#$  
for(int i=0;i<nStartPos.length;i++) aq9Ej]1b  
{ kZcGe*  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N0YJ'.=8,  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), awLSY:JI  
nStartPos,nEndPos,i); GwG(?_I"  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MEtKFC|p  
fileSplitterFetch.start(); ]XWtw21I1  
} D/z*F8'c  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &}0#(Fa`  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); )>pIAYCVP  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", D e$K  
nEndPos = " + nFileLength); )$O'L7In&  
// fileSplitterFetch[nPos.length-1].start(); 3)l<'~"z<  
o%h[o9i  
#BI6+rfv|  
//等待子线程结束 , lBHA+@  
//int count = 0; h0l_9uI  
//是否结束while循环 ei[,ug'  
boolean breakWhile = false; =[)2DJC  
<}%gZ:Z6g  
vfh\X1Ui}  
while(!bStop) '=UsN_@  
{ n,p \~Tu,  
write_nPos(); U.ew6`'Te  
Utility.sleep(500); C-(O*hK  
breakWhile = true; xz}=C:s  
F[X;A\  
Fn;Gq-^7@  
for(int i=0;i<nStartPos.length;i++) W)`H(J  
{ f=>ii v  
if(!fileSplitterFetch.bDownOver) h~#.s*0.F  
{ Hc\oR(L  
breakWhile = false; irn }.e  
break; -)e(Qt#ewl  
} %,udZyO3uR  
} WwLV^m]  
if(breakWhile) &Z+.FTo  
break; NDG?X s [2  
"ZG2olOqLI  
"gXvnl  
//count++; #aadnbf  
//if(count>4) bFfDaO<k  
// siteStop(); Rts}y:44  
} UJ&gm_M+kL  
%vU*4mH  
3`ze<K((  
System.err.println("文件下载结束!"); _2xYDi  
} ^E3 HY@j  
catch(Exception e){e.printStackTrace ();} B,A\/%<  
} '~pZj"uy  
NOtwgZ-  
E{'\(6z_  
//获得文件长度 (=tu~ ^  
public long getFileSize() 8qs8QK  
{ rU7t~DKS  
int nFileLength = -1; 9|>5;Ej  
try{ T{Yk/Z/}?  
URL url = new URL(siteInfoBean.getSSiteURL()); *35o$P46  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wtfM }MW\  
httpConnection.setRequestProperty("User-Agent","NetFox"); D!bi>]Yd  
<-!' V,c  
)umW-A  
int responseCode=httpConnection.getResponseCode(); h6e,w$IL  
if(responseCode>=400) :a M@"#F  
{ nY?X@avo>  
processErrorCode(responseCode); n:%A4*  
return -2; //-2 represent access is error !jN$U%/,%.  
} X+//$J  
^ANz=`N5,  
mz^[C7(q'(  
String sHeader; Q0TKM >  
6`)Ss5jzk  
u6P U(f  
for(int i=1;;i++) #s-li b  
{ ''CowI  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); QtfLJ5vi  
//Utility.log(in.readLine()); PML84*K -  
sHeader=httpConnection.getHeaderFieldKey(i); ;}Acy VV  
if(sHeader!=null) 2spK#0n.HV  
{ mCEWp  
if(sHeader.equals("Content-Length")) CdiL{zH\3  
{ [.4D<}e  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); V(n3W=#kky  
break; N{fYO4O  
} Y1 6pT  
} =L}$#Y8?  
else aGmbB7[BZ  
break; Wr.~Ns <  
} rXnG"A  
} GC~N$!*  
catch(IOException e){e.printStackTrace ();} +Z%8X!Q  
catch(Exception e){e.printStackTrace ();} t Ow[  
b/eo]Id]  
Jv:|J DZ'  
Utility.log(nFileLength); t($z+ C<  
6bt{j   
9;EY3[N  
return nFileLength;  SwmX_F#_  
} A>}]=Ii/  
bqUQadDB  
0"=}d y  
//保存下载信息(文件指针位置) x`p3I*_HT5  
private void write_nPos() .y~~[QF}8  
{ "RsH'`  
try{ )jN fQ!?/  
output = new DataOutputStream(new FileOutputStream(tmpFile)); edh<L/%D  
output.writeInt(nStartPos.length); '5n=tRx  
for(int i=0;i<nStartPos.length;i++) JLV?n,nF  
{ NKw}VW'|  
// output.writeLong(nPos); OGU#%5"<  
output.writeLong(fileSplitterFetch.nStartPos); p:8]jD@}%  
output.writeLong(fileSplitterFetch.nEndPos); )1]LoEdm`  
} h3kBNBI )  
output.close(); =|bW >y  
} eR5+1b  
catch(IOException e){e.printStackTrace ();} nB86oQ/S  
catch(Exception e){e.printStackTrace ();} 1V1T1  
} ki|w?0s  
j_~lc,+m  
'#x<Fo~hT  
//读取保存的下载信息(文件指针位置) Q$DF3[NC  
private void read_nPos() k3t2{=&'&x  
{ [0hZg  
try{ 7$I *ju_  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `z3"zso  
int nCount = input.readInt(); BcD%`vGJ  
nStartPos = new long[nCount]; e\>g@xE%  
nEndPos = new long[nCount]; 2E}^'o  
for(int i=0;i<nStartPos.length;i++) =;HmU.Uek%  
{ @5(HRd  
nStartPos = input.readLong(); `pd1'5Hm  
nEndPos = input.readLong(); ;V3d"@R,  
} YiPp#0T[Gx  
input.close(); J*O$)K%Hx  
} ' k[gxk|d2  
catch(IOException e){e.printStackTrace ();} G6x2!Ny  
catch(Exception e){e.printStackTrace ();} sOW,hpNW  
} F`YxH*tO7  
Z'z~40Bda  
S~ 3|  
private void processErrorCode(int nErrorCode) ]j?Kn$nv*S  
{ JSm3ZP|GqJ  
System.err.println("Error Code : " + nErrorCode); T89VSB~  
} f7QX"p&P  
SvGs?nUU  
s *1%I$=@  
//停止文件下载 E|Z7art  
public void siteStop() R|H_F#eVn}  
{ \:wLUGFl 5  
bStop = true; \ g[A{  
for(int i=0;i<nStartPos.length;i++) 6WnGP>tc.  
fileSplitterFetch.splitterStop(); 7 }sj&  
yw)Ztg)  
|1(9_=i'  
} m =2e1wc  
} /I&b5Vp  
//负责部分文件的抓取 =Z(#j5TGvH  
**FileSplitterFetch.java ;]^JUmxU[d  
*/ ^@..\X9  
package NetFox; +bK.{1  
mg^\"GC*8  
#`H^8/!e  
import java.io.*; gJ>HFid_C  
import java.net.*; Af"vSL  
cZ~\jpK  
'%"#]  
public class FileSplitterFetch extends Thread { p,w6D,h  
Ey "<hAF  
wc'K=;c  
String sURL; //File URL lCyp&b#(L  
long nStartPos; //File Snippet Start Position XL7jUi_4:L  
long nEndPos; //File Snippet End Position n`hes_{,g  
int nThreadID; //Thread's ID s~6irf/  
boolean bDownOver = false; //Downing is over 5K*-)F ]  
boolean bStop = false; //Stop identical kY6))9 O  
FileAccessI fileAccessI = null; //File Access interface -m~[z  
\;A\ vQ[  
D0&{iZ(  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException z[wk-a+w  
{ Kv:ih=?  
this.sURL = sURL; E qva] 4  
this.nStartPos = nStart; a JDu_  
this.nEndPos = nEnd; 6gfdXVN5  
nThreadID = id; qqYH}%0dz  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Up$vBE8i]  
} k]`3if5>  
[]M+(8Z_P  
U q6..<#  
public void run() n[/|M  
{ %j=,c{`Q  
while(nStartPos < nEndPos && !bStop) 7>m#Y'ppl@  
{ YtrMJ"  
VRoeq {  
$*H>n!&  
try{ LHWh-h(s  
URL url = new URL(sURL); u[oYVpe)IG  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &7X0 ;<  
httpConnection.setRequestProperty("User-Agent","NetFox"); >:`Y]6z  
String sProperty = "bytes="+nStartPos+"-"; ca_8S8lv  
httpConnection.setRequestProperty("RANGE",sProperty); UmU=3et<Wj  
Utility.log(sProperty); y*6r&989  
5\tYs=>b<  
yXw xq(32  
InputStream input = httpConnection.getInputStream(); BI=Ie?  
//logResponseHead(httpConnection); g5to0  
\?fl%r2  
m-a _<xo  
byte[] b = new byte[1024]; +* )Qi)  
int nRead; 8L 9;VY^Y  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1W HR;!u  
{ ? F f w'O  
nStartPos += fileAccessI.write(b,0,nRead); H2RNekck  
//if(nThreadID == 1) ,Fg&<Be}Jx  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0r=Lilu{q  
} y\ @;s?QL  
ASaG }h  
!U/: !e`N  
Utility.log("Thread " + nThreadID + " is over!"); (.!q~G  
bDownOver = true; _ #l b\  
//nPos = fileAccessI.write (b,0,nRead); );;UNO21+  
} Z-H Kdv!d  
catch(Exception e){e.printStackTrace ();} u6jJf@!ws  
} (s{%XB:K  
} s:cS 9A8  
0tB9X9:,  
Zk}e?Grc  
//打印回应的头信息 rsP-?oD8)  
public void logResponseHead(HttpURLConnection con) 2#1FI0,Pa*  
{ $X~=M_ W  
for(int i=1;;i++) =W !m`  
{ +.\JYH=yEr  
String header=con.getHeaderFieldKey(i); ^ I,1kl~i  
if(header!=null) rf1nC$Sop  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;Xgy2'3  
Utility.log(header+" : "+con.getHeaderField(header)); g)&-S3\  
else uD:O[H-x  
break; r:Cad0xj;^  
} Q:VD 2<2  
} ,bmTB ZV  
a$t [}D2  
+I\ bs.84  
public void splitterStop() ?67j+)  
{ |_[mb(<|  
bStop = true; w6Tb<ja  
} ieS5*@^k  
q}BQu@'H  
^Z:x poz,  
} 6nGDoW#  
N'm:V  
PLo.q|%  
/* Z*]n]eS  
**FileAccess.java /'VCJjzZ  
*//文件访问(定位,写) ocgbBE  
package NetFox; ~T4 =Id  
import java.io.*; Z/x<U.B  
(%+DE4?  
&|E2L1  
public class FileAccessI implements Serializable{ {/0,lic  
<O\z`aA'q  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 FT (EH  
RandomAccessFile oSavedFile; [V jd )%  
long nPos; y'yaCf  
ha8do^x  
}.b[az\T  
public FileAccessI() throws IOException H V   
{ Y @.JW  
this("",0); (uV7N7 <1  
} U-n33ty`H  
ax>c&%vo  
(vj2XiO^+  
public FileAccessI(String sName,long nPos) throws IOException zLh ~x  
{ rX{|]M":T  
oSavedFile = new RandomAccessFile(sName,"rw"); =h_4TpDQ  
this.nPos = nPos; \v-> '  
oSavedFile.seek(nPos); zRE7 w:  
} Zp__  
acGmRP9g  
wH${q@z_  
public synchronized int write(byte[] b,int nStart,int nLen) 06Hn:IT18  
{ 3&?Tc|F+  
int n = -1; HZK0Ldf  
try{ ]-PF?8  
oSavedFile.write(b,nStart,nLen); h0^V!.- 5  
n = nLen; <&L;9fr  
} =v;-{oN!  
catch(IOException e) ZA9']u%EJ  
{ W>DpDrO4ml  
e.printStackTrace (); +j@|D@z  
} M2zfN ru  
dU&.gFw1  
>$Fc=~;Ba  
return n; mML^kgy\N  
} U<6k!Y9ny  
?Y hua9  
3mm`8!R  
} 5W{>5.Arx)  
~y|%D;  
A|>C3S  
/* q90S>c,  
**SiteInfoBean.java NI^Y%N  
*/ lMm-K%(2  
package NetFox; 4 ^+hw;  
ASYUKh,h  
vSnb>z1  
public class SiteInfoBean { %cm5Z^B1"  
a<Ns C1  
FQ-(#[  
private String sSiteURL; //Site's URL M5x!84  
private String sFilePath; //Saved File's Path pz$$K?  
private String sFileName; //Saved File's Name NqwVs VL  
private int nSplitter; //Count of Splited Downloading File [{{?e6J  
3,F/i+@  
mm{U5  
public SiteInfoBean() AQiP2`?  
{//nSplitter的缺省值为5 - 5k4vx N}  
//default value of nSplitter is 5 OUdeQO?  
this("","","",5); Ch.T} %  
} "=".ne  
]Z84w!z  
}DM2#E`_  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =:g^_Hy  
{ hx2C<;s4  
sSiteURL= sURL; .gPsJ?b  
sFilePath = sPath; gOWyV@  
sFileName = sName; mhVoz0%1X  
this.nSplitter = nSpiltter; -DuiK:mp  
*g,?13Q_  
ZK ?x_`w  
}  R_N<j  
?}]kIK}MC  
7O9s 5  
public String getSSiteURL() f C^l9CRY  
{ pS<b|wu?f  
return sSiteURL; sTA/2d  
} =3zn Ta }  
@NH Ruk+  
XOeh![eMX  
public void setSSiteURL(String value) hv"toszj\  
{ 6>L.)V  
sSiteURL = value; tZ@ +18  
} z1FbW&V  
Qr<%rU^{.  
jF3!}*7,  
public String getSFilePath() 8x9kF]=  
{ )>Q 2G/@  
return sFilePath; dq8 /^1P  
} 6_y|4!,:W  
3'"M31iA  
op|mRJBq;  
public void setSFilePath(String value) ~4>Xi* B  
{ &53#`WgJ  
sFilePath = value; V- cuG.  
} #pe{:f?  
mWusRgj+8  
OhW=F2OIV  
public String getSFileName() >b ["T+  
{ 5j{@2]i  
return sFileName; avpw+M6+  
} @1@q6@9Tu  
0`P]fL+&  
7XDV=PQ[  
public void setSFileName(String value) Gtg)%`  
{ KyyG8;G%  
sFileName = value; ,Mhe:^3  
} gZjOlp  
ob] lCX)  
ii;WmE&  
public int getNSplitter() |tg?b&QR  
{ tRy D@}  
return nSplitter; FR}H$R7#  
} . ?p}:  
2 &Byq  
R2$U K  
public void setNSplitter(int nCount) Vf?#W,5>=  
{ t>wxK ,  
nSplitter = nCount; @"I#b99  
} BY0|exW  
} YSV,q@I&1  
?&"^\p  
} x.)gW  
/* aVP|:OAj  
**Utility.java >jX UO  
*/ ys/mv'#>  
package NetFox; B\ _u${C  
~& 5&s  
30_un  
public class Utility { ^@Qi&g`lr?  
lk +K+Ra/  
DVhTb  
public Utility() cY2-T#rL  
{ N}Ks[2  
}iSakq'  
|"yf@^kdC  
} S/-7Zo&w+  
V./w06;0  
//线程睡眠 be:phS4vz  
public static void sleep(int nSecond) %EGr0R(  
{ , Ln   
try{ b.4Xn0-M  
Thread.sleep(nSecond); vS YKe  
} #tZf>zrs  
catch(Exception e) B~>cNj<  
{ ?4ILl>*  
e.printStackTrace (); B#aH\$_U  
} h_~|O [5|)  
} R*@[P g*  
jBv$^L  
//日志 2 1~7{#  
public static void log(String sMsg) q{GSsDo-:V  
{ p%"yBpSK  
System.err.println(sMsg); ^v!im\ r  
} z9 w&uZzi  
~u0xXfv#  
A,gx5!J  
public static void log(int sMsg) }{8Fo4/  
{ HB7(  
System.err.println(sMsg); -k&{nD|  
} m`$>:B  
} V+qJrZ ,i  
g6g$nY@Jm  
hoR=%pC*  
/* 3l%,D: ?  
**TestMethod.java M{xVkXc>  
*/ @vQa\|j  
package NetFox; GzFE%< 9F  
Yu^H*b  
ufCqvv>'  
public class TestMethod { wm=RD98  
ck+b/.gw`  
zq;DIWPIoJ  
public TestMethod() 5_)@B]~nM  
{ ///xx/weblogic60b2_win.exe 5!AV!A_Jp  
try{ !\0F.*   
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); OB6J.dF[%  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); jJVT_8J  
SiteFileFetch fileFetch = new SiteFileFetch(bean); l>~`;W  
fileFetch.start(); nMG rG  
} -2\ZzK0tM  
catch(Exception e){e.printStackTrace ();} "#pzZ)Zh  
nlzW.OLM  
] *-;' *  
} fpvvV(  
!7*(!as  
-|}%~0)/bH  
public static void main(String[] args) dC` tN5  
{ st?gA"5w  
new TestMethod(); 7]|zkjgI  
} Dz`k[mI  
} jJ a V  
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