http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); \OK"r-IO
} #oxP,LR
for(int i=0;i<nEndPos.length-1;i++) [k
{ mLH,6rO9
nEndPos = nStartPos[i+1]; T!QAcO
} I4MZJAYk
nEndPos[nEndPos.length-1] = nFileLength; dS;Ui]/J
} V7$-4%NL
} Q=F^Y f
D@`"99z
TJz} 8-#t
//启动子线程 ~otV'=/my
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; RW^e#z>m"E
for(int i=0;i<nStartPos.length;i++) YAYwrKt
{ &f<Ltdw
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %Hy.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), bipA{VU
nStartPos,nEndPos,i); 17yg ~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {/K!cPp9
fileSplitterFetch.start(); vfOG(EkG.?
} 8QN/D\uq
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DXx),?s>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `{'h+v`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8o[+>W
nEndPos = " + nFileLength); HC(o;,spO
// fileSplitterFetch[nPos.length-1].start(); .MW/XnCYs4
gutf[Ksu
E rnGX#@v
//等待子线程结束 ;Wig${
//int count = 0; %oiA'hz;*
//是否结束while循环 K"g`,G6S
boolean breakWhile = false; uEDvdd#V.
z-;yDB:~t
`;z;=A*
while(!bStop) 8t1,_,2'
{ %e1`wMa
write_nPos(); MTeCmFe0;
Utility.sleep(500); ;#S4$wISw`
breakWhile = true; GE |P)VO
~0Xx]
zH1ChgF=}
for(int i=0;i<nStartPos.length;i++) XMm(D!6
{ F/0x`l
if(!fileSplitterFetch.bDownOver) H?)?(t7@
{ @po|07
breakWhile = false; 6Y/TqI[
break; Gkz~xQy1T
} sr`)l&t?
} Wj\< )cH]
if(breakWhile) lZ5TDS
break; @-Ln* 3n
02~GT_)$^
t$5)6zG
//count++; @4%x7%+[c
//if(count>4) R4[dh.lf
// siteStop(); F=8gtk|U
} }ygxmb^@Z
)}5f'TK
&*!) d"
System.err.println("文件下载结束！"); +u'y!@VV
} !-Md+I_
catch(Exception e){e.printStackTrace ();} r`!S*zK
} +B-;.]L T
R9O[`~BA2
ulxy 4] h
//获得文件长度 n%}Vd `c
public long getFileSize() h|Udw3N1L
{ j#JE4(&
int nFileLength = -1; GXx/pBdy[4
try{ J-+p]xG
URL url = new URL(siteInfoBean.getSSiteURL()); "xY]&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %eLf6|1x
httpConnection.setRequestProperty("User-Agent","NetFox"); D}7G|gX1
Nlfz'_0M
a0[Mx 4
int responseCode=httpConnection.getResponseCode(); h@"u==0
if(responseCode>=400) d@,3P)?
{ Z*Jp?[##
processErrorCode(responseCode); 34Z$a{ w
return -2; //-2 represent access is error Hy0l"CA*|
} osW"b"_f
TNK~ETE4
^=gzms
String sHeader; >ISN2Kn
GK-__Y.
]0&ExD\4
for(int i=1;;i++) b<?A
{ 2v9T&xo=
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Z=\wI:TY1
//Utility.log(in.readLine()); d ,!sZ&v
sHeader=httpConnection.getHeaderFieldKey(i); !w-`:d?
if(sHeader!=null) ThmN^N
{ qGPIKu
if(sHeader.equals("Content-Length")) }iCcXZ&5^
{ Ci?A4q$.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); q'~F6$kv5
break; CH3bpZv
} Oe:_B/l
} U6Ws#e
else G0VbW-`O
break; \:D'u<8E
} o\7q!
} |g}~7*+i
catch(IOException e){e.printStackTrace ();} *dE5yS`H
catch(Exception e){e.printStackTrace ();} x9{&rldC
sLh %k
#>/stU-
Utility.log(nFileLength); zBd)E21H
^~:&/0
o$FYCz n
return nFileLength; 9?~K"+-SI
} a="\?L5
C-6m[W8S
~'aK[3
//保存下载信息（文件指针位置） ;YK{[$F
private void write_nPos() ]fgYO+
{ !O-9W=NJ
try{ auKGm:
output = new DataOutputStream(new FileOutputStream(tmpFile)); gQ@fe3[
output.writeInt(nStartPos.length); IFg(Ze~
for(int i=0;i<nStartPos.length;i++) IR<`OA
{ lq%6~va
// output.writeLong(nPos); 4$=ATa;x-
output.writeLong(fileSplitterFetch.nStartPos); .oR_r1\y
output.writeLong(fileSplitterFetch.nEndPos); x\m?*5p
} !e"TWO*X
output.close(); wK[Xm'QTPJ
} !gfz4f&
catch(IOException e){e.printStackTrace ();} yF#:*Vz>
catch(Exception e){e.printStackTrace ();} ,9:0T LLR
} OVE5:)$x
d].(x)|st
R#QcQx
//读取保存的下载信息（文件指针位置） 4xE [S
private void read_nPos() /EpsJb`kj
{ 4Nx]*\\
try{ V9"?}cR/W;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); tbP ;iK'
int nCount = input.readInt(); ~YX!49XfHh
nStartPos = new long[nCount]; ETA 1\
nEndPos = new long[nCount]; Vu`O%[Q/
for(int i=0;i<nStartPos.length;i++) -'9sn/
{ F/qx2E$*wo
nStartPos = input.readLong(); 9se,c
nEndPos = input.readLong(); jPjFp35;zb
} @4Ox$M
input.close(); %HNe"7gk
} -brn&1oJ
catch(IOException e){e.printStackTrace ();} B[I a8t
catch(Exception e){e.printStackTrace ();} ?+WSYg0
} >,v,4,c
#CaT0#v
#)r
private void processErrorCode(int nErrorCode) @sV6g?{tI
{ jnl3P[uQ
System.err.println("Error Code : " + nErrorCode); ;6?VkF
} pd[?TyVK;
!M[a/7x,p
4l6+8/Y
//停止文件下载 e"sz jY~V
public void siteStop() ?1f(@
{ )$Erfu
bStop = true; *c[X{
for(int i=0;i<nStartPos.length;i++) f_&bwfbo
fileSplitterFetch.splitterStop(); U#jbii6e
}h6N.vz
,MtN_V-
} TzCNY@y
} !H5r+%Oo|
//负责部分文件的抓取 F`3J=AJOJ
**FileSplitterFetch.java ^E5[~C*o3
*/ ,pgpu !
package NetFox; d +]Gw
c&Mci"nj0
\>@'wl
import java.io.*; -qPYm?$
import java.net.*; `xO9xo#
g]=w_
X\I"%6$
public class FileSplitterFetch extends Thread { -L&FguoVB
kO]],Vy`
*uLlf'qU]
String sURL; //File URL llf|d'5Nl
long nStartPos; //File Snippet Start Position k0=$mmmPY
long nEndPos; //File Snippet End Position CywQ
int nThreadID; //Thread's ID )V}u}5
boolean bDownOver = false; //Downing is over H)s$0Xd
boolean bStop = false; //Stop identical TZT1nj"n
FileAccessI fileAccessI = null; //File Access interface v.08,P{b
6S;-fj
#gw ys
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException X0=#e54
{ y] Io`w(>
this.sURL = sURL; wX3x.@!:
this.nStartPos = nStart; ![wV}.}
this.nEndPos = nEnd; H+]>*^'8
nThreadID = id; g,5r)FU`
fileAccessI = new FileAccessI(sName,nStartPos);//定位 n]/7UH}(<&
} 3w=OvafT:
26YY1T\B)
7I/
public void run() Z/-!-
{ UIUCj8QJg
while(nStartPos < nEndPos && !bStop) !N4?>[E
{ : -@o3Syg
zCdQI
aj1o
try{ }";\8
URL url = new URL(sURL); FbMX?T"yH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pPUv8, %
httpConnection.setRequestProperty("User-Agent","NetFox"); RcUKe,
String sProperty = "bytes="+nStartPos+"-"; wG1A]OJl1
httpConnection.setRequestProperty("RANGE",sProperty); sLE@Cm]k
Utility.log(sProperty); :%M[|Fj
w l.#{@J]<
RO-ABFEi(
InputStream input = httpConnection.getInputStream(); @za X\
//logResponseHead(httpConnection); 7-nz'-'
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}MKm>N
byte[] b = new byte[1024]; K)|#FRPM u
int nRead; )q?z"F|
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) D2$"!7O1H
{ V+/Vk1
nStartPos += fileAccessI.write(b,0,nRead); 9kcp(
//if(nThreadID == 1) rz c}2I
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,LjB%f[
} 1LTl=tS#
f n9[Li
Y[=Gv6Fr
Utility.log("Thread " + nThreadID + " is over!"); |k~\E|^
bDownOver = true; :IFTiq5a;
//nPos = fileAccessI.write (b,0,nRead); =W1`FbR
} )NeI]p
catch(Exception e){e.printStackTrace ();} w(kN0HD
} _w+ix9Fr?
} `3!ERQU
r2A(GUz
_ukKzY
//打印回应的头信息 S$q:hXZ#e
public void logResponseHead(HttpURLConnection con) |I7-7d-;/
{ &P>wIbE
for(int i=1;;i++) j_PICv*6
{ OczVObbS
String header=con.getHeaderFieldKey(i); .@#i
if(header!=null) "R-1G/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,5" vzGLJ
Utility.log(header+" : "+con.getHeaderField(header)); t.m65
else Ug=8:a(U.
break; mA:NAV$!s
} 24_F`" :-=
} W/U&w.$
Uv,_VS(
N%{&%C6{
public void splitterStop() 7MreBs(M
{ olzP=08aaV
bStop = true; mc_`:I=
} +D|y))fE
|,F/_
gCAWRNp
} :70cOt~Z
k WYjqv
(v*$ExF
/* ot P7;l
**FileAccess.java w^09|k
*//文件访问(定位，写) l+S08IZ
package NetFox; AZcWf8
import java.io.*; 'M2Jw8i
9|O#+_=+v
5S:#I5Wa
public class FileAccessI implements Serializable{ V}ZF\SG(K
+.MHI
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %^}3:0G
RandomAccessFile oSavedFile; Pb=J4Lvz(d
long nPos; <\@JbL*
`V[{(&?,n
O$+J{@
public FileAccessI() throws IOException rWI6L3,i+
{ $d.UF!s
this("",0); -%"Kxe
} TGu`r>N51
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lil1$K: i
public FileAccessI(String sName,long nPos) throws IOException aB~?Y+m
{ qazM@
oSavedFile = new RandomAccessFile(sName,"rw"); 75}BI&t3k
this.nPos = nPos; hb7H- Z2
oSavedFile.seek(nPos); mjG-A8y
} =xFw4D9
k,O("T[
($&i\e31N
public synchronized int write(byte[] b,int nStart,int nLen) S!cc%
{ /qA\|'~
int n = -1; JX@/rXFY}
try{ %g}ri8
oSavedFile.write(b,nStart,nLen); :Zl@4}
n = nLen; HYf&0LT<11
} *j RNpB{)z
catch(IOException e) 9/TF#
{ sI/Jhw)
e.printStackTrace (); wYK-YY:Q3
} E9t[Mb %0
@#$5_uU8\(
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return n; 6VpT*,2d~
} vK z/-9im
'v iF8?_
~]P_Yd-|
} #-kG\}
rAq2
$TS4YaJ%
/* 1*<m,.$
**SiteInfoBean.java 6Pc3;X~
*/ &OD)e@Tc
package NetFox; Ub!MyXd{q
qB PUB(
Y S )Q#fP
public class SiteInfoBean { cXu"-/
~YO99PP
aj;OG^(!2_
private String sSiteURL; //Site's URL !2>MaV1,
private String sFilePath; //Saved File's Path .jW+\mIX
private String sFileName; //Saved File's Name ~ {OBRC
private int nSplitter; //Count of Splited Downloading File gwwYz]'d>r
JG-\~'9
?v?b%hK!;
public SiteInfoBean() fH[Yc>(oj
{//nSplitter的缺省值为5 dHjJLs_
//default value of nSplitter is 5 v;4l*)$)
this("","","",5); iX,|;J|]
} ,q$'hYTaJ
cC@B\Q
]/>(C76
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) _s{on/u
{ co^kP##Y
sSiteURL= sURL; Bbk=0+ ^8I
sFilePath = sPath; ^ 'W<|
sFileName = sName; ^)|8N44O
this.nSplitter = nSpiltter; G}ZJ}5h
zyb>PEd.
Hxe!68{aR
} t;g=@o9YA
GcXh V
-'ff0l
public String getSSiteURL() |Et8FR3[m
{ Qf0]7
return sSiteURL; oNW5/W2e;
} RlJt+lnV
3sUTdCnNf
K1i@.`na/$
public void setSSiteURL(String value) WBcnE(zF
{ P_Rh& gkuK
sSiteURL = value; Z]U"i1lA
} BllS3I}V
S3Q^K.e?
NrQGoAOw
public String getSFilePath() "'Bx<FA
{ [1Cs
return sFilePath; vRp#bScc
} >/W
_Z9HOl@
v[-.]b*5A$
public void setSFilePath(String value) 9 GEMmo3
{ 9@'^}c#
sFilePath = value; O}$@|w(8;
} HP/f`8
8OV;&Z,x
7sgK+ ip
public String getSFileName() 3W&f^*
{ kBF.TGT[l
return sFileName; T9&-t7:
} L$T23*9XY
:.2Tcq
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public void setSFileName(String value) hrT!S
{ |r|<cc#
sFileName = value; r .&<~x
} #ZzFAt
H@-txO1`::
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public int getNSplitter() OD;-0Bj
{ {DP%=4
return nSplitter; {nr}C4]o
} Hj\iI p
VaV(+X
rzl0*CR
public void setNSplitter(int nCount) Njp?/r
{ "xr=:[n[
nSplitter = nCount; '3<AzR2
} /=y _#l
} !L|}/u3v
7dg2-4
lMn1e6~K
/* F\K&$5J{p
**Utility.java `jI$>{oa
*/ VM.4w.})_E
package NetFox; 3zr95$Mt
\vKKq/f
:gwM$2vv
public class Utility { 2#y-3y<G
mFGiysM
yJ0q)x sS
public Utility() n7>L&?N#y#
{ 1xf Pe#
CogN1,GJ
`!um)4
} 3D2\#6yo
=sIkA)"!=
//线程睡眠 bE6:pGr
public static void sleep(int nSecond) *vqr+jr9
{ SJ%h.u@&@F
try{ 3$~oQC
Thread.sleep(nSecond); TF[8r[93
} N -z
catch(Exception e) g><*qd?t
{ # fe%E.
e.printStackTrace (); >Ohh)$
} x("V+y*
} 23iMG]J&
lx H3a :gm
//日志 nf2[hx@=U
public static void log(String sMsg) @5,Xr`]
{ G.B~n>}JU,
System.err.println(sMsg); Vx#n0z
} !5VT[w 1
OMz_xm.UPi
H[e=^JuD
public static void log(int sMsg) ^77Q4"{W
{ -|WQs'%O
System.err.println(sMsg); ,| Zkpn8
} bMvHAtp
} +\yQZ{4'@
>S[NI<=8S
'<!T'l:R:/
/* Pe`eF(J
**TestMethod.java \pwg8p[4Q
*/ 5f-eWW]!
package NetFox; ~/R bYvyA
6%\&m|S
g54b}vzm
public class TestMethod { $8;`6o`
k@=w? m
nf,u'}psdJ
public TestMethod() `;v5o4.`
{ ///xx/weblogic60b2_win.exe D6NgdE7b
try{ lG/h[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P7|x=Ew;`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); g7g^iLU
SiteFileFetch fileFetch = new SiteFileFetch(bean); Jr.4Y>;}e3
fileFetch.start(); gBPYGci2F
} ^E}};CsT
catch(Exception e){e.printStackTrace ();} @";zM&
fKkH [
FJH'!P\
} ~Kll.
Jd-u?
cwC-)#R']
public static void main(String[] args) 90[?)s
{ ;RW024
new TestMethod(); uNXKUJ V0
} $9PscubM4
} {OGv1\ol&
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