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)); @:+8?qcP
} 6n,i0W
for(int i=0;i<nEndPos.length-1;i++) |:nn>E}ZA/
{ ff]6aR/ UQ
nEndPos = nStartPos[i+1]; Vr]id
} 8<X#f !
nEndPos[nEndPos.length-1] = nFileLength; B,?T%
} %KsEB*'"
} m8A#~i .
6eLR2
C[ NSkr
//启动子线程 ;D3C>7y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; e|)hG8FlF
for(int i=0;i<nStartPos.length;i++) CyJEY-
{ 95ZyP!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T$>WE= Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9]k @Q_
nStartPos,nEndPos,i); h}[-'>{
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e%svrJ2
fileSplitterFetch.start(); eWCb73
} `#rL*;\uV
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), joFm]3$;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,f~J`3(&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", qB5j;@r
nEndPos = " + nFileLength); qraSRK5
// fileSplitterFetch[nPos.length-1].start(); :*I#n
Y\D!/T
n`#tKwWHYx
//等待子线程结束 H=<S 9M
//int count = 0; ND'E8Ke pq
//是否结束while循环 RiDJ> 6S
boolean breakWhile = false; _dqzB$JV
~5NXd)2+Ks
Z/W:97M
while(!bStop) x3hB5p$q
{ .!Oo|m`V@
write_nPos(); nL5cK:
Utility.sleep(500); CuFSeRe
breakWhile = true; J=\HO8E6>
5&QJ7B,!
pV9IHs}
for(int i=0;i<nStartPos.length;i++) C_( *>!Z%
{ caU0\VS
if(!fileSplitterFetch.bDownOver) $|L Sx
{ ynq}76 H0k
breakWhile = false; )Q=_0;#;k
break; >tYm+coS
} .8@$\ZRP
} (jnQ -
if(breakWhile) YJ^] u}
break; bn#"?6Z2
zZ7;jyD
b+%f+zz*h
//count++; v|gw9
//if(count>4) r A`V}>Xj
// siteStop(); g,Lq)'N;O
} P2NQHX
^|/TC!v]M
Tl%`P_J)-S
System.err.println("文件下载结束！"); EMh7z7}Rr
} 4QH3fTv
catch(Exception e){e.printStackTrace ();} !02`t4Zc-
} ~Y`ldL
.7Dtm<K#
lsJSYJG&
//获得文件长度 ojafy}
public long getFileSize() A0/"&Ag]
{ &TnS4O
int nFileLength = -1; 9Z|jxy
try{ rx'RSo#1O
URL url = new URL(siteInfoBean.getSSiteURL()); cA2V2S)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); - \5v^l
httpConnection.setRequestProperty("User-Agent","NetFox"); O@tU.5*$5
RM]\+BK
:{PJI,
int responseCode=httpConnection.getResponseCode(); r(6Y*<
if(responseCode>=400) }{,^@xdyW
{ FTX=Wyr
processErrorCode(responseCode); &4{KV.
return -2; //-2 represent access is error !F*5M1Kjd
} Pj[PIz
wu7Lk3
srPWE^&
String sHeader; <5-[{Q/2z
%<)2/|lCd
<C_jF
for(int i=1;;i++) w;;BSJ]+[
{ |EIng0a
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9/{(%XwX
//Utility.log(in.readLine()); ~,d,#)VE2q
sHeader=httpConnection.getHeaderFieldKey(i); "LHcB]^<
if(sHeader!=null) .S!mf
{ !Xh=k36
if(sHeader.equals("Content-Length")) QHDXW1+|^
{ z#8~iF1
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); j5QuAU8
break; .sxcCrQE
} hjU::m,WX
} "$~':) V"
else N"pc,Q\xU
break; T]R|qlZ
} 7P%%p3
} G|[=/>~B
catch(IOException e){e.printStackTrace ();} .\\DKh%
catch(Exception e){e.printStackTrace ();} S$f9m
aKV$pC<[o
+s"hqm
Utility.log(nFileLength); ,QOG!T4
'@cANGg7[
kj|6iG
return nFileLength; A|CmlAW~^
} Yw22z #K
Bp*K]3_
6~0$Z-);(
//保存下载信息（文件指针位置） Z_PNI#h*
private void write_nPos() bADnW4N`6;
{ u~r=)His
try{ K#l:wH_
output = new DataOutputStream(new FileOutputStream(tmpFile)); @+;$jRwq
output.writeInt(nStartPos.length); @v$Y7mw3D
for(int i=0;i<nStartPos.length;i++) ;5wn67'
{ `Y+J-EQ
// output.writeLong(nPos); o=u3&liBi
output.writeLong(fileSplitterFetch.nStartPos); ~fBtQGdX
output.writeLong(fileSplitterFetch.nEndPos); WKQ^NEqr3
} IW)()*8;/
output.close(); cec9l65d
} n?oW< &
catch(IOException e){e.printStackTrace ();} B5gj_^
catch(Exception e){e.printStackTrace ();} jLy
} tN[L@t9#cr
,368d9,rDz
fr,7rS/w{l
//读取保存的下载信息（文件指针位置） x"eRJii?
private void read_nPos() 7.-V-?i
{ anuL1fXO
try{ BoA/6FRi[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 68bQ;Dv
int nCount = input.readInt(); k=2Lo
nStartPos = new long[nCount]; =31"fS@
nEndPos = new long[nCount]; {.n"Z
for(int i=0;i<nStartPos.length;i++) V @rI`~$
{ %`k6w3qI
nStartPos = input.readLong(); MtM%{=&_
nEndPos = input.readLong(); y9_V
} ~aw.(A?MI
input.close(); uvgdY
} h}-3\8 >
catch(IOException e){e.printStackTrace ();} 1ofKt=|=
catch(Exception e){e.printStackTrace ();} XoXM^*Vk
} @<<<C?CTv
K*\'.~[6
909?_v
private void processErrorCode(int nErrorCode) d; [C6d
{ ?8HHA:GP
System.err.println("Error Code : " + nErrorCode); %/EVUN9=
} /TE_W@?^
|HU@ >
M\C"5%2Mu
//停止文件下载 H!vax)%-\
public void siteStop() xE1 eT,
{ liEPCWl&
bStop = true; &vHoRY
for(int i=0;i<nStartPos.length;i++) d[r#-h>dS
fileSplitterFetch.splitterStop(); kTKq/G,Ft
01[NX? qEa
yh^!'!I6u[
} z+x\(/
} vVj
//负责部分文件的抓取 BW-`t-,E;
**FileSplitterFetch.java tv>>l%
*/ H/,gro
package NetFox; z|fmrwkN'$
})uGRvz
r[1i*b$
import java.io.*; :WQ^j!9'
import java.net.*; ko1J094Y%
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tzZ63@cm
public class FileSplitterFetch extends Thread { PiYY6i0
6\L0mcXR!
k-Q%.o
String sURL; //File URL ot@|!V
long nStartPos; //File Snippet Start Position 4B=2>k
long nEndPos; //File Snippet End Position CPgCjtY
int nThreadID; //Thread's ID Yaj0;Lo[wt
boolean bDownOver = false; //Downing is over "b?v?V0%C
boolean bStop = false; //Stop identical e}mD]O}
FileAccessI fileAccessI = null; //File Access interface K )[]fm
h"`ucC8X
|}23>l7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $`APHjijN
{ d#6`&MR
this.sURL = sURL; sLh==V;9
this.nStartPos = nStart; t c[n&X
this.nEndPos = nEnd; c?P?yIz6p
nThreadID = id; )64@2~4y
fileAccessI = new FileAccessI(sName,nStartPos);//定位 BeCWa>54i
} .id)VF-l
@|LBn6q
A01AlK_B
public void run() F1iGMf-8
{ 8iW;y2qF
while(nStartPos < nEndPos && !bStop) -r#X~2tPzD
{ ##KBifU"
rxr{/8%f%
dlU'2Cl7d
try{ ur*T%b9&
URL url = new URL(sURL); |4 v0:ETb$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); AGH|"EWG
httpConnection.setRequestProperty("User-Agent","NetFox"); +$X#q8j06
String sProperty = "bytes="+nStartPos+"-"; C(S'#cm
httpConnection.setRequestProperty("RANGE",sProperty); 1<+2kBuY
Utility.log(sProperty); kR]!Vr*yh
)=\#UE+W
ktnuNsp
InputStream input = httpConnection.getInputStream(); m1n.g4Z&*
//logResponseHead(httpConnection); jxiC Kx,G
U;bK!&Z
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byte[] b = new byte[1024]; (&&4J{`W9
int nRead; y[>;]R7'
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )v]/B+
{ ng:kA%! Q
nStartPos += fileAccessI.write(b,0,nRead); n$U#:aQE
//if(nThreadID == 1) "~=mG--I
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;WgJ<&33
} 0~HKiH-
KQcs3F@t
u4.ngjJ
Utility.log("Thread " + nThreadID + " is over!"); *"WDb|PBb
bDownOver = true; SaC d0. h
//nPos = fileAccessI.write (b,0,nRead); 7uT:b!^f[
} aUxGzMZ
catch(Exception e){e.printStackTrace ();} Kh(ZU^{n
} #BJG9DFP4`
} p>vn7;s2#
I96Ci2)m
!h(|\" }
//打印回应的头信息 \(VTt|}By$
public void logResponseHead(HttpURLConnection con) bfA=3S"0
{ ,QC{3i~
for(int i=1;;i++) XGJj3-eW{
{ 76wc,+
String header=con.getHeaderFieldKey(i); l_EM8pL,f
if(header!=null) oHMo>*?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); qzI&<4
Utility.log(header+" : "+con.getHeaderField(header)); $KUos+%
else qP2ekI:y
break; \=+b}mKV m
} )foq),2
} hdnTXs@z
ET_W-
N+LL@[
public void splitterStop() =1O<E
{ O$D'.t
bStop = true; iv?gZg
} k=4N(i/s
\ {qI4=
xfy1pS.[:
} a^Tmu
[vMvV4,
RaWG w
/* lrWV#`6!+
**FileAccess.java YFE&r
*//文件访问(定位，写) _$wmI/_JM
package NetFox; WuPH'4b 5
import java.io.*; ?6L&WB
6 `Aj%1
TT50(_8
public class FileAccessI implements Serializable{ YX=2jI
BBH0OiV=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `Ja?fI'H-
RandomAccessFile oSavedFile; !>BZ6gn5
long nPos; v^)bhIPe;
=8r 0 (c
%ObLWH'
public FileAccessI() throws IOException AS E91T~
{ >ELlnE8
this("",0); }"|"Q7H
} e{X6i^% m_
c1$ngH0
u5 {JQO
public FileAccessI(String sName,long nPos) throws IOException 89n:)|rWq
{ 6(]tYcC
oSavedFile = new RandomAccessFile(sName,"rw"); aO@7O*
this.nPos = nPos; d0aCY
oSavedFile.seek(nPos); 28/ ADZ
} {cB+mh;mJ>
0{[m%eSK'
%1.]c6U
public synchronized int write(byte[] b,int nStart,int nLen) \A#1y\ok
{ A#nun
int n = -1; :8 jhiB)
try{ neXeAU
oSavedFile.write(b,nStart,nLen); -zp0S*iP7
n = nLen; ?OE.O/~l
} d"5oD@JG:
catch(IOException e) ({-GOw46
{ n6*En7IVh
e.printStackTrace (); !L;\cl
} Aub]IO~
-b9;5eS!
$we]91(::
return n; {/X4(;~0
} "p/j; 6H
/,MJq#@K
d~/q"r1"
} JCPUM*g8
#'-Sh7ycW
UK$ms~H
/* `6[I^qG".
**SiteInfoBean.java ^K7ic,{
*/ %.<H=!$
package NetFox; aWwPvd3
v~T7`
:Gu+m
public class SiteInfoBean { qS/V"|G(
4B4Z])$3
G [:N0{v5
private String sSiteURL; //Site's URL |y h\
private String sFilePath; //Saved File's Path xXY.AoO6
private String sFileName; //Saved File's Name }R)=S_j
private int nSplitter; //Count of Splited Downloading File i.xXb[M+
DNR~_3Aq
)mJf|W!Z#
public SiteInfoBean() U9&k;`
{//nSplitter的缺省值为5 9U {y1}
//default value of nSplitter is 5 op"$E1+
this("","","",5); :-iMdtm
} Ja]?&j
Z1ALq5
kW`r=u
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) OFGsjYLw
{ 6 4D]Ypx
sSiteURL= sURL; Q|,B*b
sFilePath = sPath; K*IxUz(
sFileName = sName; }m/RZP~=
this.nSplitter = nSpiltter; 2>]a)
T/c<23i
!Oj)B1gc6&
} K.%U
'`|AI:L
FVB;\'/
public String getSSiteURL() \eGKkSy
{ &(zfa&j|
return sSiteURL; f`8OM}un&
} }C /]
:^'O}2NP
b$Hz3TJ(
public void setSSiteURL(String value) xq%{}
{ BR v+.(S
sSiteURL = value; )i>[M"7
} `k;KBW
ZUp\Ep}
Y4F6qyP)"
public String getSFilePath() 1[E#vdbT
{ 4Hb $0l
return sFilePath; aup6?'G;
} dI*'!wK
DY{cQb
e,k2vp!<&
public void setSFilePath(String value) W%e_~$H0
{ Sf/q2/r?6[
sFilePath = value; x|0:P sE
} #5&jt@NS
.fzu"XAPu
cBYfXI0`
public String getSFileName() Eq^uKi
{ v8/6wy?
return sFileName; Q<6P. PTya
} mPPk)qy
SQWafD
Te{ *6-gO3
public void setSFileName(String value) BHj\G7,S
{ B|%tE{F
sFileName = value; 02JoA+
} zTo8OPr
g,]@4|
"PH6e bm
public int getNSplitter() -6=<#9R
{ )9=(|Lp
return nSplitter; `@`1pOb
} RGD]8mw
td{O}\s7D
XM|%^ry
public void setNSplitter(int nCount) i3mAfDF
{ 2UP,Tgn..
nSplitter = nCount; V%CUMH =U
} ^1jk$$f
} :XV} c(+d
DlyMJ#a
K3mAXC,d
/* ?Qqd "=k4
**Utility.java va|rO#.=
*/ C+K=[
package NetFox; .G>t72DpU
=y%rG :!
] c}91
public class Utility { JmOW~W
N;HIsOT}t
9.M{M06;
public Utility() ?mRE'#
{ {SG>'KXZ
:Dl%_l
F9XT lA
} I<h=Cj[[
$v}<'
//线程睡眠 cs_}&!c{
public static void sleep(int nSecond) 7;LO2<|1
{ h<p3'
try{ v })Q
Thread.sleep(nSecond); |G=[5e^s[
} N<JHjq
catch(Exception e) vz`@x45K
{ 59B&2861
e.printStackTrace (); tkuc/Z/@
} Xt,X_o2m|]
} )u@c3?$6
MonS hIz
//日志 ,#'7)M D8
public static void log(String sMsg) 0,FC YTtj$
{ .Gb+\E{M
System.err.println(sMsg); GVd48*
} Jp;k+"<q
lr('k`KOQ
LxJ6M/".
public static void log(int sMsg) Ff"gadRXd
{ }X$l\pm
System.err.println(sMsg); $W!]fcZlB
} . %(^mK)zQ
} <9@7,2
IftxSaP
+T_ p8W+j
/* o;J;*~g
**TestMethod.java [{F%LRCo-
*/ K6pw8
package NetFox; H`<?<ak6'M
sms1%%~
8?jxDW a
public class TestMethod { bY#;E;'7
_|n=cC4Qu
t&c&KFK)I&
public TestMethod() pZ+j[!
{ ///xx/weblogic60b2_win.exe T$b\Q
try{ D6=HYqdj
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); EI`vVI
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3-Y=EH_0
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2mJ:c
fileFetch.start(); c%<2z
} IUhp;iH
catch(Exception e){e.printStackTrace ();} (iDBhC;/B
Xt(! a
^!>.97*
} (5Ky6b9v
r7XD&Y
3sC:jIp
public static void main(String[] args) e`DsP8-&v
{ q]v,
new TestMethod(); #)i&DJ^Y
} aG3k4
} f4]&pcK
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