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http断点续传简单实现(java)

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/* 'bl%Y).9w  
**SiteFileFetch.java f P+QxOz  
*/ W5 |j1He&  
package NetFox;  Ll?g.z"  
import java.io.*; o7J{+V  
import java.net.*; mLQUcYfR  
PFm\[2  
pG~'shD~Dn  
public class SiteFileFetch extends Thread { 0juDuE?  
pcNSL'u+  
CGkI\E  
SiteInfoBean siteInfoBean = null; //文件信息Bean 4aA9\\hfGY  
long[] nStartPos; //开始位置 ,b4g.CV  
long[] nEndPos; //结束位置 Q4=|@|U0  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 &lUNy L  
long nFileLength; //文件长度 dt<~sOT3s  
boolean bFirst = true; //是否第一次取文件 Rh[Ibm56  
boolean bStop = false; //停止标志 /e .D /;]  
File tmpFile; //文件下载的临时信息 ",T` \8&@e  
DataOutputStream output; //输出到文件的输出流 svqvG7  
 tq0;^L  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) _Yy:s2I8B  
public SiteFileFetch(SiteInfoBean bean) throws IOException 9N^+IZ@l  
{ K0v.3  
siteInfoBean = bean; :,47rN,qa  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); rtus`A5p  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); yZ5 x8 8>  
if(tmpFile.exists ()) |UYED%dC  
{ oE6|Zw  
bFirst = false; viJJ e'\2  
read_nPos(); ljuNs@q  
} /7x\;&bc  
else JdO)YlM-  
{ }I]W'<jY  
nStartPos = new long[bean.getNSplitter()]; 3T?f5+@I  
nEndPos = new long[bean.getNSplitter()]; E0<)oQ0Xa>  
} &kiF/F 1  
obj!I7  
Y+@g~TE  
+2Z#M  
} \q,s?`+B  
/LF3O~Go  
05"qi6tncz  
public void run() %<AS?Ry  
{ yjFe'  
//获得文件长度 e"~)Utk  
//分割文件 @iRO7 6m  
//实例FileSplitterFetch ogJ<e_ m  
//启动FileSplitterFetch线程 9qre|AA  
//等待子线程返回 26 ?23J ;  
try{ P.h.M A]  
if(bFirst) =LK}9ViH  
{ >D~w}z/fk  
nFileLength = getFileSize(); R:f7LRF/\  
if(nFileLength == -1) ULIFSd Y  
{ {@45?L('  
System.err.println("File Length is not known!"); 5 < GDW=  
} ;y OD  
else if(nFileLength == -2) AEqq1A   
{ >(3'Tnu  
System.err.println("File is not access!"); (A uPZ  
} Zih ?Bm  
else [;Fofu Z  
{ g|4w8ry  
for(int i=0;i<nStartPos.length;i++) @hsbq  
{ EHhd;,;O  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); k}U JVH21k  
} V^2-_V]8  
for(int i=0;i<nEndPos.length-1;i++) 0bSz4<}  
{ 7k~Lttuk  
nEndPos = nStartPos[i+1]; 3S;N(A4  
} Z2bUs!0  
nEndPos[nEndPos.length-1] = nFileLength; I="oxf#q  
} cgN>3cE  
} M(2`2-/xh  
CV3DMA  
:Eo8v$W\RB  
//启动子线程 nB&j   
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;wgFr.#hp@  
for(int i=0;i<nStartPos.length;i++) t%$@fjz  
{ !+KhFC&Py  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [q3+$W \r  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^/a*.cu  
nStartPos,nEndPos,i); lkwh'@s.  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !DcX8~~@  
fileSplitterFetch.start(); {cR3.%wX  
} y 1nU{Sc@  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ag6uR(uI  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); wDw<KU1UK  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )5GQJiY  
nEndPos = " + nFileLength); yC"Zoa6YZ  
// fileSplitterFetch[nPos.length-1].start(); *<q4S(l  
I N_gF_@%  
+*.1}r&  
//等待子线程结束 EY$?^iS  
//int count = 0; P7r4ePtLk{  
//是否结束while循环 JJ-i_5\q  
boolean breakWhile = false; kFLT!k  
U&Ab# m;  
zo44^=~%  
while(!bStop) R@n5AN(  
{ /buWAX 1  
write_nPos(); ANb"oX c  
Utility.sleep(500); }e2F{pQ  
breakWhile = true; c,$mWTC  
OoM_q/oI  
&I)\*Ue2t  
for(int i=0;i<nStartPos.length;i++) [%~^kq=|  
{ jb3.W  
if(!fileSplitterFetch.bDownOver) v$3_o :  
{ `xIh\q  
breakWhile = false; MA6P"?  
break; [+gzdLad  
} 0x71%=4H^x  
} 74]a/'4  
if(breakWhile) WIG=D{\Yx  
break; vgo{]:Aj{  
VA2<r(y~(  
_+n;A46  
//count++; WW6yFriuW  
//if(count>4) ugxw!cj  
// siteStop(); \u8,!) 4i  
} HamEIL-l.  
oLP]N$'#  
Ut_mrb+W  
System.err.println("文件下载结束!"); 6|oWaA\gI  
} k/bque  
catch(Exception e){e.printStackTrace ();} :l`i4kx  
} v:A:37#I  
5[<F_"x  
0#nXxkw  
//获得文件长度 @wZ_VE7B  
public long getFileSize() Gjh7cm>  
{ ;rdLYmmx^  
int nFileLength = -1; m1Z8SM+  
try{ EqU[mqeF  
URL url = new URL(siteInfoBean.getSSiteURL()); 'bO? =+c  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9r*T3=u.S  
httpConnection.setRequestProperty("User-Agent","NetFox"); 4T^WRS  
\ku{-^7  
tzN;;h4C  
int responseCode=httpConnection.getResponseCode(); 74OM tLL$  
if(responseCode>=400) PiQs><FK8  
{ ';V+~pi  
processErrorCode(responseCode); P &._ -[  
return -2; //-2 represent access is error LA Vgf>  
} (3*Hl  
m$: a|'mS  
$B/cj^3  
String sHeader; 7FFYSv,[:  
C#0Wo  
l.)!jWY  
for(int i=1;;i++) )g F9D1eA  
{ o%5Ao?z~  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); FvP1;E  
//Utility.log(in.readLine()); b)@x@3"O  
sHeader=httpConnection.getHeaderFieldKey(i); W=w@SO_?wp  
if(sHeader!=null) V> SA3  
{ @jeV[N,0  
if(sHeader.equals("Content-Length")) u'> CU  
{ "YZ`g}sG  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); gk` .8o  
break; \ed(<e>  
} :b-(@a7>  
} \_'pUp22  
else "de:plMofy  
break; iiscm\  
} w{IqzmPiH  
} ^" -2fJ  
catch(IOException e){e.printStackTrace ();} 2S/7f:  
catch(Exception e){e.printStackTrace ();} 8uiQm;W  
z{x -Vfd  
|<$O5b'  
Utility.log(nFileLength); jL$X3QS:  
h,g~J-x`|  
yAe}O#dy  
return nFileLength; j!dklQh0  
} /2q%'"x(  
m|[ Hhw=f  
<s >SnOD  
//保存下载信息(文件指针位置) cs)hq4-L`  
private void write_nPos() @P?*<b{  
{ [R$4n-$  
try{ M\3!elp2z  
output = new DataOutputStream(new FileOutputStream(tmpFile)); =Ju}{ bX  
output.writeInt(nStartPos.length); *XuzTGa"  
for(int i=0;i<nStartPos.length;i++) l ki(_ @3  
{ ,D1QJPM  
// output.writeLong(nPos); b3H;Ea?^^<  
output.writeLong(fileSplitterFetch.nStartPos); 3@PVUJ0B|  
output.writeLong(fileSplitterFetch.nEndPos); lk|/N^8M  
} _U %B1s3y  
output.close(); zFI bCv8  
} r%4:,{HF  
catch(IOException e){e.printStackTrace ();} sr4K-|@  
catch(Exception e){e.printStackTrace ();} % |V:F.f  
} whshjl?a  
hS  Sq=(S  
( _2eiE71  
//读取保存的下载信息(文件指针位置) )I@iW\`7  
private void read_nPos() ]@EjKgs  
{ =0S7tNut  
try{ eYFCf;  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); vs +N{ V  
int nCount = input.readInt(); iBQftq7  
nStartPos = new long[nCount]; +t f=  
nEndPos = new long[nCount]; 2B# \683  
for(int i=0;i<nStartPos.length;i++) Wo&i)S<i0F  
{ +x`tvo  
nStartPos = input.readLong(); ]?2AFkF  
nEndPos = input.readLong(); BLRrHaX0  
} .|K5b]na  
input.close(); -{?Rq'H  
} T!n<ya!  
catch(IOException e){e.printStackTrace ();} S $Wd}2>  
catch(Exception e){e.printStackTrace ();} ;iEqa"gO  
} ^U1;5+2G+~  
wBf bpoE7  
<NUZPX29  
private void processErrorCode(int nErrorCode) xucV$[f  
{ ,AJd2ix  
System.err.println("Error Code : " + nErrorCode); 0o#lB^e;l  
} -`( :L[  
)S]c'}^  
0 [s1!Cm!i  
//停止文件下载 eu~;G H  
public void siteStop() w v1R ]3}  
{ ixp%aRRP  
bStop = true; /w|YNDA]j  
for(int i=0;i<nStartPos.length;i++) @{bf]Oc  
fileSplitterFetch.splitterStop(); hX^XtIC=  
ka(xU#;  
yO !*pC  
} tlW}lN}  
} bY`k`3v  
//负责部分文件的抓取 Uc/%4Gx   
**FileSplitterFetch.java cD 1p5U  
*/ =Vi+wH{xM  
package NetFox; %T&kK2d;  
I?1^\s#L  
[P<oyd@#  
import java.io.*; )t|M)zJ  
import java.net.*; (|WqOwmoUt  
F:n7yey  
(LnKaf8  
public class FileSplitterFetch extends Thread { 8r~4iVwg  
$+Xohtt  
S2`p&\Ifn  
String sURL; //File URL >OQ<wO6  
long nStartPos; //File Snippet Start Position I!{5*~ 3  
long nEndPos; //File Snippet End Position \=w|Zeu{l  
int nThreadID; //Thread's ID j_k!9"bt  
boolean bDownOver = false; //Downing is over FN G]  
boolean bStop = false; //Stop identical NL1Ajms`  
FileAccessI fileAccessI = null; //File Access interface rK"x92P0  
i`X/d=  
vzfWPjpKW  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >1W)J3  
{ tYVmB:l  
this.sURL = sURL; sVGyHA  
this.nStartPos = nStart; 9Y0w SOSW  
this.nEndPos = nEnd; 6z~6o0s~  
nThreadID = id; aK 'BC>uFI  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 U1I2+;"#A  
} )!3sB{ H  
o4U9jU4<"  
xV%6k{_:G  
public void run() 8BvonY t=8  
{ Qv-@Zt!8  
while(nStartPos < nEndPos && !bStop) %7O?JI [  
{ 85;b9k&\M  
#2iD'>bQ  
`gKf#f  
try{ V] Et wA  
URL url = new URL(sURL); t\$U`V)  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0|; .6\  
httpConnection.setRequestProperty("User-Agent","NetFox"); HK+/:'P u  
String sProperty = "bytes="+nStartPos+"-"; 7^T^($+6s&  
httpConnection.setRequestProperty("RANGE",sProperty); "*O4GPj  
Utility.log(sProperty); ^*\XgX  
hQNe;R5  
,.gQ^^+=  
InputStream input = httpConnection.getInputStream(); ){r2T1+-%  
//logResponseHead(httpConnection); "`[!Lz  
WMMO5_M z  
S>.F_Jl  
byte[] b = new byte[1024]; ZtHm\VTS  
int nRead; FYS/##r  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) E\;ikX&1  
{ vy,&N^P  
nStartPos += fileAccessI.write(b,0,nRead); {,OS-g  
//if(nThreadID == 1) z6py"J@  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M# 18H<]  
} =+w*gDr  
2YuN~-  
0P>OJYFr'  
Utility.log("Thread " + nThreadID + " is over!"); wM_c48|d  
bDownOver = true; fIGFHZy,  
//nPos = fileAccessI.write (b,0,nRead); *._|-L  
} rxO2QQ%V  
catch(Exception e){e.printStackTrace ();} ) _ I,KEe  
} )etmE  
} #:3r4J%+~  
Mj0Cat=  
zW{ 6Eg  
//打印回应的头信息 .BTx&AqU  
public void logResponseHead(HttpURLConnection con)  e/e0d<(1  
{ ^o<:;{  
for(int i=1;;i++) ioIv=qGdiP  
{ c|wCKn}`  
String header=con.getHeaderFieldKey(i); 5!fSW2N  
if(header!=null) 0yof u  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [ET6(_=b  
Utility.log(header+" : "+con.getHeaderField(header)); !"4w&bQ  
else !awh*Xj6  
break; _=`x])mM  
} qc!xW ,I  
} KS!yT_O  
993d/z|DX  
L@|#Bbmx  
public void splitterStop() 0*(K DDv  
{ M1=_^f=&.  
bStop = true; ;R1B9-,  
} .A<sr  
m^$5K's&  
N2~$r pU3  
} +BB0wY  
.K9l*-e[=  
A|vP$zy  
/* rnvQ<671W  
**FileAccess.java }z'DWp=uN  
*//文件访问(定位,写) 4: sl(r  
package NetFox; me./o(!?  
import java.io.*; ^tE_LL+ji|  
)*[ ""&  
J/S{FxNe]  
public class FileAccessI implements Serializable{ 7z<Cu<  
nUqy1(  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 oeN zHp_  
RandomAccessFile oSavedFile; xYT}>#[  
long nPos; _'c+fG \  
{,f[r*{Y  
^g]xU1] *  
public FileAccessI() throws IOException ]C)|+`XE@  
{ 3i(Jon/p  
this("",0); ]31$KBC  
} :`zV [A:D  
VG\mo?G  
oWD)+5. ]  
public FileAccessI(String sName,long nPos) throws IOException R92R}=G!  
{ ~u2w`H?V  
oSavedFile = new RandomAccessFile(sName,"rw"); _?Ckq  
this.nPos = nPos; 6h@+?{F.  
oSavedFile.seek(nPos); k#jm7 +  
} v$JLDt_  
CXa Ld7nMX  
".M:`BoW4  
public synchronized int write(byte[] b,int nStart,int nLen) ]+lF=kkc %  
{ {_Np<r;j<  
int n = -1; iPkT*Cl8  
try{ t[q3 {-  
oSavedFile.write(b,nStart,nLen); ~,G]glu8  
n = nLen; JilKZQmk  
} H` Lu"EK  
catch(IOException e) Xr2 Wa  
{ * 2%oZX F  
e.printStackTrace (); YR8QO-7 .)  
} /gX%ABmS  
:P"9;$FY  
]]3Q*bq4  
return n; 'y eh7oR  
} Uk|9@Auav  
)=Y-f?o!  
yW:AVqE)t  
} v'$ykZ!Z  
LiF.w:}  
'1lx{U zD  
/* T5V$wmB\W  
**SiteInfoBean.java b2W;|  
*/ xNx`J@xt$  
package NetFox; z(r" JNO@  
y "<JE<X  
~(M*6b  
public class SiteInfoBean { " _mmR M  
l2r>|CGQ[  
fA;x{0CAMX  
private String sSiteURL; //Site's URL R,XD6'Q  
private String sFilePath; //Saved File's Path br10ptEx  
private String sFileName; //Saved File's Name }el,^~  
private int nSplitter; //Count of Splited Downloading File Wl?<c uw00  
OY$7`8M[  
A03I-^0g+  
public SiteInfoBean() 5'),)  
{//nSplitter的缺省值为5 E=3#TBd  
//default value of nSplitter is 5 C?bXrG\  
this("","","",5); "rL"K  
} Un~]Q?w  
t% <pbZO  
kK08W3@&t  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ya;@<b  
{ F1zT )wW  
sSiteURL= sURL; 7ucx6J]c  
sFilePath = sPath; 6_x}.bkIx=  
sFileName = sName; L)@`58Eil  
this.nSplitter = nSpiltter; Cx[4 /~_<  
VzesqVx  
e+wd>iiB  
} ,"o \_{<z  
Bh?;\D'YC  
DZue.or  
public String getSSiteURL() OjZ@_V:  
{ ,tZwXP{  
return sSiteURL; 3>+;G4  
} (yfTkBy  
D6w0Y:A{.  
n[@Ur2&)  
public void setSSiteURL(String value) :&m(WZ \  
{ lK-I[i!  
sSiteURL = value; cu-WY8n  
} `f'P  
:R)IaJ6)  
Qxwe,:  
public String getSFilePath() &+v&Dd&  
{ 'g#GUSXfj  
return sFilePath; o#i {/# oF  
} z2V!u\It  
Ot?rsr  
"q$M\jK#V  
public void setSFilePath(String value) T1E{NgK  
{ U&6f}=v C  
sFilePath = value; E O5Vg  
} |fUSq1//  
pPE4~g 05h  
=["GnL*!0  
public String getSFileName() /SiQw7yp%  
{ L-XTIL$$  
return sFileName; C.@TX  
} }^H_|;e1p  
<*[(t;i  
y.zW>Mfl  
public void setSFileName(String value) /vu7;xVG  
{ jzQgD ed ]  
sFileName = value; O'k"6sBb  
} YW*ti|u|w  
i |t$sBIh  
M<SZ7^9<  
public int getNSplitter() .FeEK(  
{ TtzB[F  
return nSplitter; H_{Yr+p  
} !59q@M ya[  
R#0UwRjeF  
C-8@elZ1  
public void setNSplitter(int nCount) mwt3EV5  
{ L(.5:&Y=`  
nSplitter = nCount; PH6uP]  
} s^cHR1^  
} u!O)\m-  
JH 8^ZP:d'  
c5JxKU_  
/* jN'zNOV~  
**Utility.java .k}h'nE  
*/ 0VPa=AW  
package NetFox; bS*9eX=K  
Hg]r5Fe/c  
,ecFHkT>  
public class Utility { Lx.X#n.]T  
KyjN'F$  
2gA6$s7  
public Utility() OmsNo0OA  
{ _f/6bpv  
yovC~  
~x2azY2DP  
} vForj*Xo  
ikUG`F%W  
//线程睡眠 LBTf}T\  
public static void sleep(int nSecond) Gx!Y 4Q}-  
{ tks1*I$S<  
try{ k/>k&^?  
Thread.sleep(nSecond); HUZI7rC[=)  
} p~qdkA<  
catch(Exception e) n*uT  
{ FN\*x:g  
e.printStackTrace (); BlnR{Y  
} .~u[rc|<  
} A`71L V%  
t^ Ge "  
//日志 F JCs$0  
public static void log(String sMsg) g8k S}7/  
{ 2{|Z?3FJ^  
System.err.println(sMsg); 8 kvF~d ;  
} *O_>3Hgl  
ia@ |+r  
&n9&k Em  
public static void log(int sMsg) > 9.%hSy  
{ F_G .$a Cc  
System.err.println(sMsg); agt/;>q\~  
} 1%ENgb:8  
} qA0PGo  
!#d5hjoX  
>$,P )cB'  
/* ?8N^jjG  
**TestMethod.java _iu~vU)r  
*/ 't6l@ _x  
package NetFox; X!_&%^L'  
<2N{oK.  
A3)"+`&PUl  
public class TestMethod { C#-HWoSi  
]~2iducB,  
eR%\_;}7;  
public TestMethod() i\<S ;  
{ ///xx/weblogic60b2_win.exe ?r 0rY?  
try{ fV@ [S  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )r^vrCNy>  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); URceq2_  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3Q'vVNFh<  
fileFetch.start(); C$q};7b1N  
} A 0v=7 ]  
catch(Exception e){e.printStackTrace ();} d?&`Z Vl  
!KMl'kswe:  
yX4 Vv{g  
} Qo)Da}uo20  
$33E-^  
<pfl>Uf  
public static void main(String[] args) -w*fS,O  
{ ^R=`<jx   
new TestMethod(); udu<Nis4  
} s3eS` rK-  
} gUNhN1=  
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