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)); Fda<cS]
} )lH?XpfTjm
for(int i=0;i<nEndPos.length-1;i++) 5.5dB2w
{ w;{k\=W3Ff
nEndPos = nStartPos[i+1]; zg|yW6l)9
} 2lXsD;[
nEndPos[nEndPos.length-1] = nFileLength; "52wa<MVJ
} pOw4H67
} !tX14O~B-
0H;dA1
lzl4pnj
//启动子线程 n |.- :Zy
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; AE^&hH0^
for(int i=0;i<nStartPos.length;i++) M>1V3sM
{ b%T-nY2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kZf7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), AGOK%[[Ws
nStartPos,nEndPos,i); }2DeqY
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GTJ\APrH
fileSplitterFetch.start(); M`iJ6L
} qfN<w&P
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vWzNsWPK"{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); LF{qI?LG
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )pJ}o&J
nEndPos = " + nFileLength); P),%S9jP;
// fileSplitterFetch[nPos.length-1].start(); NL2n\%n
H+_oK ]/
r}03&h~Hc&
//等待子线程结束 QT^( oog=
//int count = 0; :tR%y"
//是否结束while循环 E39:}_IV
boolean breakWhile = false; Cg)#B+
%l3RM*zb
vad" N
while(!bStop) <}B|4($
{ KasOh"W.P
write_nPos(); +Y 3_)
Utility.sleep(500); y$\K@B4
breakWhile = true; cS{l2}E
iHQFieZ.E
h_y<A@[P}
for(int i=0;i<nStartPos.length;i++) ChGwG.-%L
{ h-!(O^M
if(!fileSplitterFetch.bDownOver) eYR/kZ%<
{ ZOS{F_2.
breakWhile = false; 5p"*nkF
break; =oiY'}%(i
} b*.)m
} #v~zf@<KLB
if(breakWhile) Na3tK}x
break; xp><7{
XwlUkw"q
}R}tIC-:
//count++; AGrGZ7p]
//if(count>4) F fl`;M
// siteStop(); 1\zI#"b ^
} Zj`eR\7~
1mA)=hu
?;uzx7@F
System.err.println("文件下载结束！"); .[K{;^>
} @0B<b7Jv
catch(Exception e){e.printStackTrace ();} F~RUb&*/<
} ~V5k
ho^1T3
.%~ L
//获得文件长度 dbnH#0i
public long getFileSize() a$;+-Y
{ qxd{c8
int nFileLength = -1; &+%CC
try{ ]l+2Ca:-[j
URL url = new URL(siteInfoBean.getSSiteURL()); <|.S~HLTQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'fK_J}+P
httpConnection.setRequestProperty("User-Agent","NetFox"); ]1D>3
7W}~c/%
6jF~zI^
int responseCode=httpConnection.getResponseCode(); kv`x
if(responseCode>=400) r!Mr\
{ MZL~IX
processErrorCode(responseCode); /[{?zS{
return -2; //-2 represent access is error mc9$"
} <-FZ-asem
kC LeHH|K
T5Pc2R
String sHeader; ?&/9b)cS
|#!25qAT
P[gk9{sv
for(int i=1;;i++) QC ]z--wu
{ |bd5aRS9
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); DYzVV(_J"
//Utility.log(in.readLine()); #gsAwna3
sHeader=httpConnection.getHeaderFieldKey(i); PB }$.8
if(sHeader!=null) -Ca.:zX
{ xbn+9b
if(sHeader.equals("Content-Length")) 4b7}Sr=`
{ 5'oWd e
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #9 }Oqm
break; %tQIKjsVaY
} _^&oNm1
} NK"y@)%0
else D8Ni=.ALL
break; I`5MAvP
} +{Q\B}3cj1
} i<%(Z[9Lk
catch(IOException e){e.printStackTrace ();} |wK)(s
catch(Exception e){e.printStackTrace ();} cH2 nG:H
TR ]lP<m
iW |]-Ba\
Utility.log(nFileLength); Az0Yt31=
{/B) YR
s'LG3YV-<
return nFileLength; hoU&'P8
} Rzb663d
(y(V,kXwa8
TXrC5AJx
//保存下载信息（文件指针位置） oZOFZ-<
private void write_nPos() s'/.eaV_
{ ym,S/Uz
try{ ]YOQIzkL4}
output = new DataOutputStream(new FileOutputStream(tmpFile)); BB>7%~3f
output.writeInt(nStartPos.length); Txp~&a03
for(int i=0;i<nStartPos.length;i++) _VY]
{ 9rA3qj%
// output.writeLong(nPos); Zz/w>kAG*{
output.writeLong(fileSplitterFetch.nStartPos); BAzqdG
output.writeLong(fileSplitterFetch.nEndPos); ^!kvgm<{$
} 1b_->_9
output.close(); k$I[F<f
} Dw.>4bA.
catch(IOException e){e.printStackTrace ();} 7a@V2cr@
catch(Exception e){e.printStackTrace ();} ,ew<T{PL
} ",~3&wx
'# (lq5 c
?$r+#'asd(
//读取保存的下载信息（文件指针位置） '*)!&4f
private void read_nPos() U?>zq!C&R
{ ;#f%vs>Y7i
try{ faMUd#o&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); y{jv-&!xB
int nCount = input.readInt(); )03.6Pvs
nStartPos = new long[nCount]; j-A S {w
nEndPos = new long[nCount]; b*p,s9k7
for(int i=0;i<nStartPos.length;i++) av`b8cGg
{ tgrQ$Yjk
nStartPos = input.readLong(); 4tq>Lx^5U
nEndPos = input.readLong(); Tri.>@-u
} <`MHra8
input.close(); KP:O]520
} ~vF.k,
catch(IOException e){e.printStackTrace ();} L^ +0K}eD
catch(Exception e){e.printStackTrace ();} 75^-93
} gHox{*hb[
mZq*o<kTA
;$|+H"g|
private void processErrorCode(int nErrorCode) qBCZ)JEN#U
{ Sb,{+Wk
System.err.println("Error Code : " + nErrorCode); RNi&OG(
} KTf!Pf?g
2etlR
7:1Hgj(
//停止文件下载 ?m~x%[Vn
public void siteStop() zGz5|u
{ +<3tv&"
bStop = true; ]B5\S
for(int i=0;i<nStartPos.length;i++) ]v9<^!
fileSplitterFetch.splitterStop(); @aj"12
5_`.9@eh.
BwL:B\
} 071wo7
} ]k,fEn(
//负责部分文件的抓取 65<p:
**FileSplitterFetch.java C?E;sRr0
*/ f$H"|Mbe
package NetFox; FE_n+^|k<
F.@yNr"
y ruN5
import java.io.*; Wt4!XV
import java.net.*; %!eK"DKG^
x"N,oDs
:X;8$.z
public class FileSplitterFetch extends Thread { 4vy!'r@
|d,1mmv@K
g[eI-J+F
String sURL; //File URL S++}kR);
long nStartPos; //File Snippet Start Position ZZeqOu7^
long nEndPos; //File Snippet End Position g5Hs=c5=\
int nThreadID; //Thread's ID b LxV
boolean bDownOver = false; //Downing is over 9Y/c<gbY
boolean bStop = false; //Stop identical HVk3F|]V
FileAccessI fileAccessI = null; //File Access interface :b.#h7Qt<
<p<gx*%
z?yADYr9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8:0l5cZE
{ !CsoTW9C:
this.sURL = sURL; SJy?^
this.nStartPos = nStart; J0s8vAs
this.nEndPos = nEnd; p*dez!
nThreadID = id; 3Um\?fj>}(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Q2tGe~H
} V;)'FJ)]
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.Q?AzU,2D
public void run() Mr`u!T&sc
{ 4y P $l
while(nStartPos < nEndPos && !bStop) !UgJ^v
{ =e ;\I/
52:oe1-8
; 4S#6#
try{ ;JAe=wt^'I
URL url = new URL(sURL); 3J[P(G>Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;w@:
httpConnection.setRequestProperty("User-Agent","NetFox"); pR~PB
String sProperty = "bytes="+nStartPos+"-"; i#Wl?(-i
httpConnection.setRequestProperty("RANGE",sProperty); ]")i~-|R
Utility.log(sProperty); vKI,|UD&-
qA03EU
&[kwM395
InputStream input = httpConnection.getInputStream(); LoTq2/
//logResponseHead(httpConnection); GLk7#Y
3S.rIai+
}~A-ELe:
byte[] b = new byte[1024]; y`\/eX
int nRead; .oSKSld
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @NV$!FB<
{ ,ciNoP*-~%
nStartPos += fileAccessI.write(b,0,nRead); (-~tb-
//if(nThreadID == 1) |1t30_ /gS
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Nzr zLK
} qdcCX:Z<
d/* [t!
x9@%L{*
Utility.log("Thread " + nThreadID + " is over!"); (j cLzq
bDownOver = true; U2SxRFs >
//nPos = fileAccessI.write (b,0,nRead); HPU7 `b4
} v3~,1)#aI
catch(Exception e){e.printStackTrace ();} ) d\Se9!
} dnN"
} 0gt/JI($
H:0-.a^ZS
8LiRZ"
//打印回应的头信息 43 |zjE
public void logResponseHead(HttpURLConnection con) Oj<2_u
{ ~ae68&L6
for(int i=1;;i++) F.T~txQ~u
{ i:W oT4
String header=con.getHeaderFieldKey(i); YF."D%?
if(header!=null) 3xj<ATSe
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9K)OQDv%6D
Utility.log(header+" : "+con.getHeaderField(header)); .Yh-m
else {Y IVHl
break; SXgpj
} . vYGJ8(P
} D./e|i?
tuUk48!2I
W_M]fjL.
public void splitterStop() 4jar5Mz
{ Z0E+EMo
bStop = true; czedn_}%Q
} 5oORwOP
N7Ne
*A8CJ
} N8m^h:b
XrBLw}lD`N
(o e;pa
/* /V3*[
**FileAccess.java Z1q'4h=F.
*//文件访问(定位，写) *]F3pP[
package NetFox; 3>?ip;
import java.io.*; /i$&89yod
A0&~U0*(~
V+(
public class FileAccessI implements Serializable{ )_+#yaC
o F@{&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >Z>*Iz,LP
RandomAccessFile oSavedFile; #7'ww*+
long nPos; ^=W%G^jJy
SDTX0v
$\0j:<o
public FileAccessI() throws IOException :X@;XEol~
{ spFsrB
this("",0); \`4}h[
} DY,Sfh;tp
nA+[[(6
S: /ShT
public FileAccessI(String sName,long nPos) throws IOException l*%?C*
{ /$ L;m
oSavedFile = new RandomAccessFile(sName,"rw"); 1!=$3]l0Lj
this.nPos = nPos; 'v\!}6
oSavedFile.seek(nPos); Sgr<z d'b
} &Vl,x/
y ?Q"-o (
}S%a]
public synchronized int write(byte[] b,int nStart,int nLen) 2]Y (<PC
{ ,j2qY'wi
int n = -1; !%5{jO1
try{ in B}ydk
oSavedFile.write(b,nStart,nLen); KF7f<
n = nLen; QmgwIz_
} 2X6y^f';\
catch(IOException e) d6(qc< /!r
{ >%d]"]
e.printStackTrace (); ?J)%.~!
} 9lny[{9
)Cx8?\/c=x
y)/d-
return n; u4Vc:n
} \ fwf\&
)\^%w9h
d8Upr1_
} hRA.u'M
Qaagi `
&I d^n
/* S%Ja:0=}?
**SiteInfoBean.java ^hbh|Du
*/ )?4m}
package NetFox; V <k_Q@K
u1nv'\*
c~c3;
public class SiteInfoBean { <5L!.Ci
-3KB:K<
rhL<JTS
private String sSiteURL; //Site's URL 2|Tt3/Rn
private String sFilePath; //Saved File's Path ,PIdPaV--
private String sFileName; //Saved File's Name R]ppA=1*_l
private int nSplitter; //Count of Splited Downloading File b^A&K@[W#,
0BE%~W
2%WZ-l!i
public SiteInfoBean() eKu&_q
{//nSplitter的缺省值为5 iUl{_vb
//default value of nSplitter is 5 #0^QUOp
this("","","",5); w7%N=hL1
} .+B!mmp
Fs&m'g
TF3Tha]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) OFUN hbg
{ dQizM^j
sSiteURL= sURL; H) (K
sFilePath = sPath; pX*mX]
sFileName = sName; d2(eX\56Z
this.nSplitter = nSpiltter; kXG+zsT
^,`Lt *
AM Rj N;
} 6^ KDc
I>P</TE7
&[3!Lk`.0
public String getSSiteURL() EA8(_}
{ Ye )(9
return sSiteURL; 8zpK;+
} 'TbA^U[
r Ssv^W+
T!;<Fy"p
public void setSSiteURL(String value) auGt>,Zj\Q
{ ;=e A2
sSiteURL = value; s)To#
} 1pz6e8p:m
fc!%W#-
B8IfE`
public String getSFilePath() FyY;F;4P
{ |d:URuG~:I
return sFilePath; +rql7D0st
} mCq*@1Lp9
bH,Jddc
Je?V']lm
public void setSFilePath(String value) uAJ_`o[
{ C-2n2OM.
sFilePath = value; .b]oB_
} bz>#}P=58G
4/d#)6
'ugG^2Y
public String getSFileName() DPe`C%Oc1
{ >U) ,^H(
return sFileName; j5ui
} n_c0=YH
Lnj5EY er
3@}_ F<"*
public void setSFileName(String value) c=| a\\
{ cb UVeh7Q
sFileName = value; +bQn2PG=
} =h&^X>!
rP3)TeG6
,p 'M@[
public int getNSplitter() S"_vD<q
{ r+Z+x{
return nSplitter; 95(VY)_6#A
} S)[2\Z{**T
Xt~/8)&
S[ 2`7'XV
public void setNSplitter(int nCount) Ads^y`b
{ Bq2}nDP
nSplitter = nCount; LLU>c]a
} d3 N %V.w
} 5aWKyXBIx
z&-`<uV~
h?CNChRJs
/* t8^*s<O
**Utility.java 0\gE^=o[
*/ w$t2Hd
package NetFox; f,?7,?x
DSnsi@Mi
s ^}V
public class Utility { 1yKf=LZ^
x'
I~mw\K{.3M
public Utility() [hiOFmMJZ-
{ P089Mh9
wYF)G;[wM
^.<IT"
} DdFVOs|
)lW<:?k
//线程睡眠 8)H"w$jq
public static void sleep(int nSecond) %R_8`4IQ
{ =|G PSRQ
try{ 5N[Y2
Thread.sleep(nSecond); M.l;!U!}
} Ao]F_hZ
catch(Exception e) 0umfC
{ "5YsBih
e.printStackTrace (); )<~b*^kl\
} >MhkNy
} T
, n EeI&
//日志 \[8I5w-
public static void log(String sMsg) %8$wod6
{ pFG~XW
System.err.println(sMsg); |Rab'9U^
} ]9x30UXLwD
Nls|R
LXx3
public static void log(int sMsg) !}vz_6)
{ 4b<:67 %
System.err.println(sMsg); b0&dpMgh:
} ?}Mv5SO
} 20Rgw
,qr)}s-
iE&`Fhf?
/* cq!>B{
**TestMethod.java D #A9
*/ T8RQM1D_s
package NetFox; 9^}GUJy?
}SOj3.9{c
XCt}>/"s\h
public class TestMethod { %b_zUFHPp
z24-hC
bGSgph
public TestMethod() _x>u"w
{ ///xx/weblogic60b2_win.exe 8,H
try{ 3*'!,gK~[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); HWHGxg['r
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 00$W>Gr
SiteFileFetch fileFetch = new SiteFileFetch(bean); -MU^%t;-
fileFetch.start(); `rM-b'D
} EGa}ml/G
catch(Exception e){e.printStackTrace ();} +XIN-8
`@:^(sMo
0_j!t
} `9F'mT#o/
K1$Z=]a+
\"uR&D
public static void main(String[] args) T0Gu(c`1d
{ *=ALns?y
new TestMethod(); apYf,"|9
} N(IUNL
} ,0])]
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