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http断点续传简单实现(java)

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/* eP~3m  
**SiteFileFetch.java }#1.$a  
*/ | +;ZC y  
package NetFox; DG;u_6;JR  
import java.io.*; XtO..{qU  
import java.net.*; ftY&Q#[  
#)S}z+I  
b]]k\b  
public class SiteFileFetch extends Thread { .!~ysy  
a >fA-@  
9,fV  
SiteInfoBean siteInfoBean = null; //文件信息Bean Mzg'$]N  
long[] nStartPos; //开始位置 |6d:k~p  
long[] nEndPos; //结束位置 /eHf8l  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 lSR\wz*Fk  
long nFileLength; //文件长度 L~ax`i1:"  
boolean bFirst = true; //是否第一次取文件 XF: wsC  
boolean bStop = false; //停止标志 &3/`cl[+  
File tmpFile; //文件下载的临时信息 Sp[9vlo8  
DataOutputStream output; //输出到文件的输出流 q5g_5^csM{  
HZ<#H3_ix  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) il >+jVr  
public SiteFileFetch(SiteInfoBean bean) throws IOException }F1Asn  
{ .U(6])%;@  
siteInfoBean = bean; iY>x x~V  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));  5V<6_o  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 9y\nO)\Tv  
if(tmpFile.exists ()) w8D8\`i!"  
{ _LF'0s*  
bFirst = false; pXNhU88  
read_nPos(); V.3#O^S  
} n^QDMyC;I  
else m@nGXl'!  
{ fyUW;dj  
nStartPos = new long[bean.getNSplitter()]; qF3S\ C  
nEndPos = new long[bean.getNSplitter()]; gS(JgN  
} f]1 $`  
>kAJS??  
1%M^MT%&  
leHKBu'd  
} QqL?? p-S>  
~oOv/1v},  
`*CoVx~fk  
public void run() b5g^{bzwu  
{ *Iw19o-I  
//获得文件长度 ] Q^8 9?  
//分割文件 ])pX)(a  
//实例FileSplitterFetch -6 v?iiZr  
//启动FileSplitterFetch线程 lU|ltnU  
//等待子线程返回 ? Zv5iI  
try{ @uC-dXA"  
if(bFirst) 3znhpHO)  
{ M/V"Ke"N  
nFileLength = getFileSize(); N+SA$wG  
if(nFileLength == -1) [9?]|4  
{ !5+9~/;  
System.err.println("File Length is not known!"); PvUY Q>Kw  
} ~=wBF  
else if(nFileLength == -2) ,hK =x  
{ w}}+8mk[  
System.err.println("File is not access!"); tc;$7F ;  
} .*k!Zl*  
else ;2 o{ 6  
{ Qvny$sr2  
for(int i=0;i<nStartPos.length;i++) hW,GsJ,  
{ ve#[LBOC8  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); dd=5`Bo9Yh  
} ]Gl_L7u`  
for(int i=0;i<nEndPos.length-1;i++) 3I?yRE  
{ !4F@ !.GG!  
nEndPos = nStartPos[i+1]; ;Xidv9c  
} d{!zJ+n  
nEndPos[nEndPos.length-1] = nFileLength; J!rZs kd  
} -'W:P'BG  
} 7({.kD6  
$o\U q  
"z.!h(Eq  
//启动子线程 y^p%/p%  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 17Q* <iCs  
for(int i=0;i<nStartPos.length;i++) !/&~Feb  
{ tORDtMM9+  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), GmGq69]J*  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), n;b 9f|&z  
nStartPos,nEndPos,i); 0g#?'sD  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); QqY42hR  
fileSplitterFetch.start(); 'U`I  
} DF#WQ8?$]  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9 DXu*}  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]:^kw$  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", d@|j>Z  
nEndPos = " + nFileLength); '9wD+'c=A  
// fileSplitterFetch[nPos.length-1].start(); s|!b: Ms`  
>|T?87  
=7P; /EV  
//等待子线程结束 /=OSGIJzm  
//int count = 0; b!37:V\#}  
//是否结束while循环 X>jwjRK $  
boolean breakWhile = false; I^ A01\p  
;rta#pRn  
4d'tK^X  
while(!bStop) tX *L_  
{ :kI x?cc  
write_nPos(); r3{o _w  
Utility.sleep(500); .yj=*N.  
breakWhile = true; w1A&p  
~pSD|WX  
-ap;Ul?  
for(int i=0;i<nStartPos.length;i++) s.dn~|a  
{ Mz{ Rh+gS  
if(!fileSplitterFetch.bDownOver) m9>nv rQ  
{ 1J *wW# e  
breakWhile = false; {K0T%.G  
break; Iei4yDv ;  
} <F.Ol/'h  
} v:T` D  
if(breakWhile) &akMj@4;R  
break; f&cG;Y  
SS~Txt75m  
:U[_V4? 7  
//count++; $v oyXi`*  
//if(count>4) #XY]@V\  
// siteStop(); +ow ^xiD  
} N$,)vb<  
LA@}{hU  
&Y=NUDt_  
System.err.println("文件下载结束!"); GRV9s9^  
} YL=k&Q G  
catch(Exception e){e.printStackTrace ();} sBu"$ "]  
} ;^8^L'7cr  
>`\*{]  
K+$c,1wb  
//获得文件长度 A07 P$3>/W  
public long getFileSize() Pd;ClMa%  
{ EhUy7b,1_  
int nFileLength = -1; yaR;  
try{ ^{K8uN7  
URL url = new URL(siteInfoBean.getSSiteURL()); 7VXeu+-P  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n)7icSc  
httpConnection.setRequestProperty("User-Agent","NetFox"); (MIw$)#^  
?-84_i  
qtH&]Suu,  
int responseCode=httpConnection.getResponseCode(); v(7A=/W_  
if(responseCode>=400) "AK3t' jF*  
{ 1DcarF  
processErrorCode(responseCode); Mqtp}<*@-  
return -2; //-2 represent access is error hw'2q9J|  
} &"h!SkX/  
_Lb& 2 PAG  
RZtL<2.@  
String sHeader; )IhY&?jk?  
` j<tI6[e  
wqOhJYc  
for(int i=1;;i++) oX4uRc7wR  
{ &P3vcB  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Xh/av[Q  
//Utility.log(in.readLine()); {LD8ie|x1`  
sHeader=httpConnection.getHeaderFieldKey(i); NGY I%:  
if(sHeader!=null) "\[>@_p h  
{ U}0/V c26  
if(sHeader.equals("Content-Length")) \veL5  
{ dZgfls  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); G]1pGA;  
break; 5w1[KO#K|  
} [alXD_  
} m^.C(}  
else >[@d&28b%  
break; @ 1A_eF  
} ?63JQ.;  
} vNSf:5H$  
catch(IOException e){e.printStackTrace ();} !?*!"S-Sl  
catch(Exception e){e.printStackTrace ();} [;AcV73  
U9 *2< c  
6{X>9hD  
Utility.log(nFileLength); I}IW!K  
p ri{vveN@  
gu[dw3L  
return nFileLength; 'e64%t  
} oLMi vy4  
CWQ2iu<_0  
m5aaY  
//保存下载信息(文件指针位置) I7^X;Q F  
private void write_nPos() k& s7 -yY  
{ V9_HC f  
try{ vqi$}=%n?W  
output = new DataOutputStream(new FileOutputStream(tmpFile)); X2YOD2<v  
output.writeInt(nStartPos.length); )"uG*}\?b  
for(int i=0;i<nStartPos.length;i++) <,4(3 >js  
{ veg!mY2&  
// output.writeLong(nPos); /$,=>  
output.writeLong(fileSplitterFetch.nStartPos); D#1~]d  
output.writeLong(fileSplitterFetch.nEndPos); 1T,PC?vr{  
} by[i"!RCu  
output.close(); i%4k5[f.:  
} i(iP}: 3  
catch(IOException e){e.printStackTrace ();} ?(8%SPRk  
catch(Exception e){e.printStackTrace ();} y?#J`o- O  
} B!ibE<7,  
(x0*(*A}  
lkg*AAR?'  
//读取保存的下载信息(文件指针位置) Z[S+L"0  
private void read_nPos() hyfnIb@~}  
{ PZRn6Tc  
try{ _C,@eu"9V  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f\U&M,L\ '  
int nCount = input.readInt(); @[lc0_ b  
nStartPos = new long[nCount]; 7O{O')o!  
nEndPos = new long[nCount]; 89#0vG7m  
for(int i=0;i<nStartPos.length;i++) =e8L7_;  
{ E0^%|Mh]b  
nStartPos = input.readLong(); 3,L3C9V'  
nEndPos = input.readLong(); hUvuq,LH_  
} 65#:2,s  
input.close(); !LOors za  
} *3`oU\r  
catch(IOException e){e.printStackTrace ();} bTQa'y`3  
catch(Exception e){e.printStackTrace ();} "Lq|66  
} k+#l;<\2  
6y,P4O*q  
"=\_++  
private void processErrorCode(int nErrorCode) oXlxPN39  
{ fCf#zV[  
System.err.println("Error Code : " + nErrorCode); W#jZRviyq!  
} EH*ym#Y  
O0wCb  
m_!vIUOz  
//停止文件下载 yC 7Vb P  
public void siteStop() H]$=*(aje  
{  +iH30v  
bStop = true; Jhsv2,8 {  
for(int i=0;i<nStartPos.length;i++) q X%vRf0  
fileSplitterFetch.splitterStop(); n~)HfY  
rH&r6Xv[  
%:w% o$  
} "4ozlWx  
} s w.AfRQP  
//负责部分文件的抓取 EhIV(q9x  
**FileSplitterFetch.java seuN,jpt  
*/ Yl&tkSw46  
package NetFox; FfxX)p1t  
SQt|(r)  
wL-ydMIx  
import java.io.*; 7}'A)C>J;  
import java.net.*; od}EM_  
vf'cx:m  
OVUs]uK  
public class FileSplitterFetch extends Thread { Xm8Z+}i  
I51oG:6fR?  
J(EaE2  
String sURL; //File URL X(y  
long nStartPos; //File Snippet Start Position YF! &*6m  
long nEndPos; //File Snippet End Position JU'WiR bcb  
int nThreadID; //Thread's ID :Dk@?o@2;C  
boolean bDownOver = false; //Downing is over 9jMC |oE  
boolean bStop = false; //Stop identical  H\=LE  
FileAccessI fileAccessI = null; //File Access interface g>!:U6K  
2&gd"Ak(  
jKj=#O  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException sArje(5Eo  
{ t8A kdSU0  
this.sURL = sURL; p<HTJ0  
this.nStartPos = nStart; NDRW  
this.nEndPos = nEnd; v;fJM5PA  
nThreadID = id; s ~Lfi.  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 'n^2|"$sH  
} ;v,9 v;T  
Jm %ynW  
%Ui{=920  
public void run() %wt2F-u  
{ i5 L:L  
while(nStartPos < nEndPos && !bStop) ` /I bWu  
{ !f\?c7  
Gpdv]SON{  
dU ,)TKQ  
try{ $bZu^d,  
URL url = new URL(sURL); oNuPP5d[]  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \6SMn6a4  
httpConnection.setRequestProperty("User-Agent","NetFox"); PG6[lHmi  
String sProperty = "bytes="+nStartPos+"-"; X(GmiH /E  
httpConnection.setRequestProperty("RANGE",sProperty); C#Hcv*D  
Utility.log(sProperty); (!ZQ  
Ig1lol:;  
|;A9A's  
InputStream input = httpConnection.getInputStream(); 9Hf*cQ  
//logResponseHead(httpConnection); cW)Oi^q%o2  
NZo<IKD$  
oe(9mYWKa6  
byte[] b = new byte[1024]; t1e4H=d>  
int nRead; 5c: '>  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) IjG5X[@  
{ 1mJbQ#5  
nStartPos += fileAccessI.write(b,0,nRead); tS\=<T  
//if(nThreadID == 1) ZjU=~)O}H  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GA|/7[I}  
} JsmbW|t^  
^uyNv-'F  
E tJ~dL)  
Utility.log("Thread " + nThreadID + " is over!"); VLcyPM@"Q!  
bDownOver = true; !}>eo2$r^  
//nPos = fileAccessI.write (b,0,nRead); klgv{_b  
} n$.1Wk"  
catch(Exception e){e.printStackTrace ();} gB]C&Q  
} |Du,UY/  
} >vlQ|/C  
?. zu2  
bK3B3r#$  
//打印回应的头信息 |}_gA  
public void logResponseHead(HttpURLConnection con) H1` rM^,%A  
{ HUj+-  
for(int i=1;;i++) [O^}rUqq  
{ 0TTIaa$  
String header=con.getHeaderFieldKey(i); CE~r4  
if(header!=null) f%2%T'Q  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); hzaLx8L  
Utility.log(header+" : "+con.getHeaderField(header)); :3*`IB !  
else U r^YG4(  
break; C/F@ ]_y  
} L)q`D2|'  
} Uh|TDuM  
]{YN{  
C@%iQ]=  
public void splitterStop() jEUx q%BH  
{ B-!guf rnY  
bStop = true; 8NnhT E  
} z>6.[Z(T  
c  Qld$  
u\`/Nhn  
} ~6p5H}'H1  
RNGO~:k?r  
P,(9cyS{  
/* ~\2;i]|  
**FileAccess.java Ll,I-BQ 9  
*//文件访问(定位,写) mHKJ  
package NetFox; t-_#Q bzE{  
import java.io.*; f, |QAj=a  
MzcB3pi  
&a.']!$^"  
public class FileAccessI implements Serializable{ $( S*GF$S  
y)P&]&"?  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 c8T/4hU MN  
RandomAccessFile oSavedFile; Tru c[A.2Z  
long nPos; Zw+=ng.q?  
8pqs?L@W  
Gc wt7~  
public FileAccessI() throws IOException FtE90=$  
{ ^Sw2xT$p{j  
this("",0); \H^;'agA  
} )&>L !,z  
 q$F)!&  
(}G!np  
public FileAccessI(String sName,long nPos) throws IOException Ddb-@YD&+0  
{ ?fV?|ZGZI  
oSavedFile = new RandomAccessFile(sName,"rw"); {o( * f  
this.nPos = nPos; G(3;;F7"  
oSavedFile.seek(nPos); )`^ /(YG  
} byafb+x  
G%;kGi`m  
IAYACmlN&  
public synchronized int write(byte[] b,int nStart,int nLen) ]a M-p@  
{ ((qGh>*  
int n = -1; vTdUuj3N  
try{ sJOV2#r  
oSavedFile.write(b,nStart,nLen); B;V5x/  
n = nLen; ~Po<(A}`f  
} 4h;4!I|  
catch(IOException e) n,CD  
{ !:3^ hb  
e.printStackTrace (); M_Bu,<q^  
} Y17hOKc`  
8&%Cy'TIz4  
JRXRi*@  
return n; ZNi +Aw$u  
} teAukE=}  
SyAo, )j  
E4=qh1d  
} m^Glc?g<  
4Ac}(N5D@  
)9B:Y;>)  
/* FNC[59   
**SiteInfoBean.java 1eHe~p ,  
*/ i3P9sdTD  
package NetFox; Hs$'0:  
~q 7;8<U  
q4/909x=  
public class SiteInfoBean { yPoSJzC=[  
gGEIK0\{  
z3W3=@  
private String sSiteURL; //Site's URL o5SQ1;`   
private String sFilePath; //Saved File's Path =G4u#t)  
private String sFileName; //Saved File's Name *1$    
private int nSplitter; //Count of Splited Downloading File P_&p=${  
nM8[  
*GJ:+U&m[  
public SiteInfoBean() b!^@PIX  
{//nSplitter的缺省值为5 |NJ}F@t/5  
//default value of nSplitter is 5 a~opE!|m  
this("","","",5); w^Ag]HZN  
} 6Hk="$6K  
~>g+2]Bn>$  
-9d%+O~v6~  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &?y7I Pp  
{ dw9T f^V  
sSiteURL= sURL; +P)ys#=  
sFilePath = sPath; {~'H  
sFileName = sName; &iBNO,v  
this.nSplitter = nSpiltter; !zR)D|w&  
w#9_eq|3  
Xh}&uZ`A  
} 9 I{/zKq  
8Q=ZH=SQK  
: y1Bt+Fp  
public String getSSiteURL() '1-maM\r  
{ pawl|Z'Ez  
return sSiteURL; aCl A{  
} g*J@[y;  
~x#vZ=]8  
Bd# TUy  
public void setSSiteURL(String value) |55dbL$w  
{ 64umul  
sSiteURL = value; +rc SL8C  
} Q|c|2byb  
i%F<AY\O)  
Z!_n_F k  
public String getSFilePath() n Q-mmY>#  
{ `N'V#)Pi  
return sFilePath; ,[l`zp  
} p0VUh!  
#K|9^4jt  
50$W0L$  
public void setSFilePath(String value) + >nr.,qo3  
{ :o8MUXH$  
sFilePath = value; '!Wvqs  
} }`_(<H  
o\!qcoE2W  
#]Y*0Wzpfn  
public String getSFileName() T$P-<s  
{ 5JSrrpGr  
return sFileName; x)oRSsv!Tr  
} :FHA]oec1  
Ej"u1F14J  
B(,:haAr  
public void setSFileName(String value) ue\t,*KYd  
{ |`0n"x7  
sFileName = value; pW|u P8#  
} tTuX\;G  
=J/FJb  
{dzoEM[ 1s  
public int getNSplitter() =;ICa~`C;  
{  3+U]?7t  
return nSplitter; G%:G eW  
} &%,DZA`  
+}JM&bfK  
J=H)JH3  
public void setNSplitter(int nCount) e fO jTA%  
{ k\aK?(.RC7  
nSplitter = nCount; ahGT4d`)9  
} /XbW<dfl  
} c^9tYNn  
#ekM"p  
{HrZ4xQnpV  
/* iqPBsIW  
**Utility.java *y]+dK&-  
*/ K{=PQ XSU  
package NetFox; RUo9eQIPD  
-LWK*q[J;*  
+B"0{>n}F  
public class Utility { ;rR/5d1!  
%!|O.xxRR  
nc?B6IV  
public Utility() lm0N5(XP  
{ Tv$sqVe9  
$[ z y  
wT_h!W  
} ^3~e/PKM  
| C+o;  
//线程睡眠 bw S*]!*  
public static void sleep(int nSecond) j-b*C2l  
{ DBgMC"_   
try{ n}nEcXb  
Thread.sleep(nSecond); `u_Qa  
} ?Bx./t><  
catch(Exception e) +%0z`E\?M#  
{ ',=g;  
e.printStackTrace (); \ |!\V  
} D4u% 6R|F  
} 57I}RMT"  
p]T"|!d  
//日志 7Y( 5]A9=  
public static void log(String sMsg) {eT.SO  
{ Lx[ ,Z,kD  
System.err.println(sMsg); v"O5u%P  
} (< c7<_-H  
`V!>J 1x  
LKF/u` 0dP  
public static void log(int sMsg) Acm<-de  
{ =o7}]k7  
System.err.println(sMsg); [\e@_vY@OH  
} =xN= #  
} xge7r3i  
Dr#c)P~Wd  
T)iW`vZg8  
/* S4o$t -9l  
**TestMethod.java tkKJh !Q7  
*/ {6Au3gt/  
package NetFox; rofNZ;nu  
q_fam,9  
}JgYCsF/f  
public class TestMethod { 8|g<X1H{M  
8y2+&#$  
dK9Zg,DZL  
public TestMethod()  kLP0{A  
{ ///xx/weblogic60b2_win.exe UQ?%|y*Kc  
try{ X$n(-65  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); A[N{  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0 p uY"[c  
SiteFileFetch fileFetch = new SiteFileFetch(bean); HIvZQQW|  
fileFetch.start(); j}JZ  
} q6d~V] 4:  
catch(Exception e){e.printStackTrace ();} ,FSrn~-j9  
^+|De}`u  
| A)\ :  
} b^CNVdo'  
L"(4R^]  
 H`QQG!  
public static void main(String[] args) D-p.kA3MJ  
{ 5Rv+zQ#GR  
new TestMethod(); N"7]R[*  
} t0E51Ic@  
} g_.^O$}  
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