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)); pTzfc`~xv
} &xjeZh4-
for(int i=0;i<nEndPos.length-1;i++) WgC*bp{
{ #Cz6c%yK
nEndPos = nStartPos[i+1]; Q=cbHDB
} C@q&0\HN
nEndPos[nEndPos.length-1] = nFileLength; D[iIj_CKQ
} H=k`7YN
} O-K!Bv^ Q
^_^rI+cTX1
x1ID6kI[{*
//启动子线程 X>6VucH{\
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; uyDYS
for(int i=0;i<nStartPos.length;i++) ~*Ir\wE
{ dwt<s[k
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u:7=Yy :
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Lu?)Rya
nStartPos,nEndPos,i); /,Sd
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q`X5W
fileSplitterFetch.start(); v^_<K4N`
} `[J(au$z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K\GIh8L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); j']Q-s(s
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", f3]u-e'b
nEndPos = " + nFileLength); k^PqB+P!
// fileSplitterFetch[nPos.length-1].start(); .DkDMg1US
5bzYTK&-
TAt9+\'
//等待子线程结束 +6* .lRA
//int count = 0; B<Ynx_95
//是否结束while循环 ~-w
boolean breakWhile = false; ljrA^P,>P
~Zd n#z\
$PQlaivA
while(!bStop) cMEM}Qh T
{ 3*gWcPGe
write_nPos(); q[3b i!Q
Utility.sleep(500); Pk; 9\0k7
breakWhile = true; #dGg !D
ZN ?P4#ZS
$u4esg
for(int i=0;i<nStartPos.length;i++) 6]}Xi:I
{ :;XHA8
if(!fileSplitterFetch.bDownOver) 32IN;X|
{ XjwTjgL<
breakWhile = false; DOWUnJ;5
break; Y4Z?`TL
} "A:wWb<m
} Tj{!Fx^H
if(breakWhile) ZtEHP`Iin
break; .6E7 R
!+M H?A
f41!+W=
//count++; R^F99L
//if(count>4) `4&\ %9
// siteStop(); DZXv3gnX
} \Rp)n=|
P N_QK Z
_TB\@)\
System.err.println("文件下载结束！"); T"Q4vk,3*J
} ZF;S}1
catch(Exception e){e.printStackTrace ();} "MXd!
} 2uWzcy ?F
SAG)vmm
Q$,8yTM
//获得文件长度 $Y,]D*|"K
public long getFileSize() X2i<2N*@
{ ~ilbW|s?=k
int nFileLength = -1; YQN=.Wtc
try{ aXC`yQ?
URL url = new URL(siteInfoBean.getSSiteURL()); ;gm){ g
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /,0t,"&Aqa
httpConnection.setRequestProperty("User-Agent","NetFox"); ]hvB-R16f
v!F(DP.)Z
K)Db3JIIk
int responseCode=httpConnection.getResponseCode(); g\(7z P
if(responseCode>=400) $zmES tcm
{ Ky nZzR
processErrorCode(responseCode); \k1Wh-3
return -2; //-2 represent access is error ?o.G@-
} J*U(f{Q(
c= a+7>
^1cqx]>E
String sHeader; (tq)64XVz
:za!!^
RycEM|51V
for(int i=1;;i++) (`!| Uf$
{ >uuX<\cW
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #Y18z5vo
//Utility.log(in.readLine()); ~!A,I 9
sHeader=httpConnection.getHeaderFieldKey(i); @6D<D6`
if(sHeader!=null) AN~1E@"
{ d,QJf\fc"
if(sHeader.equals("Content-Length")) ZY/at/v
{ 56bB~=c
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); v}_$9&|S
break; s{q2C}=$?D
} D!mhR?t
} +bO{UC[
else T]vD ,I+
break; DSjo%Brd-
} yQx>h6
} }]s~L9_z['
catch(IOException e){e.printStackTrace ();} 9xKFX|*$
catch(Exception e){e.printStackTrace ();} Zka;}UL&Q
1OGlD+f
gEe}xI
Utility.log(nFileLength); 2)8lJXM$L
nK|";
8EE7mEmLH
return nFileLength; FCe503qND$
} b]Y,& 8}[+
wk/->Rz
SA&wW\Ym]
//保存下载信息（文件指针位置） 'RA[_Z
private void write_nPos() 53T2w,?
{ |-|BM'Y
try{ 4Ek< 5s[
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;|^fAc~9{r
output.writeInt(nStartPos.length); f@}(<#
for(int i=0;i<nStartPos.length;i++) WIGb7}egR
{ W[?B@sdSZ
// output.writeLong(nPos); 9BY b{<0tS
output.writeLong(fileSplitterFetch.nStartPos); <h}?0NA4
output.writeLong(fileSplitterFetch.nEndPos); bCrB'&^t
} j>T''Tf
output.close(); "L)pH@)
} m88~+o<G%
catch(IOException e){e.printStackTrace ();} aj,ZM,Ad
catch(Exception e){e.printStackTrace ();} qb<gh D=j
} 3edAI&a5
b#m47yTW9<
a9I8WQ
//读取保存的下载信息（文件指针位置） 9j"\Lr*o"
private void read_nPos() /7#&qx8
{ b?$09,{0
try{ L8G4K)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); yR!>80$j
int nCount = input.readInt(); <(MFEIt
nStartPos = new long[nCount]; >H1d9y+Z
nEndPos = new long[nCount]; (wfg84
for(int i=0;i<nStartPos.length;i++) _e3'f:
{ qcot T\rq
nStartPos = input.readLong(); T82_`u
nEndPos = input.readLong(); pUr[MnQLf
} -0`hJ_(
input.close(); x\DkS,O
} m&q;.|W
catch(IOException e){e.printStackTrace ();} r Lh h
catch(Exception e){e.printStackTrace ();} twtDyo(\
} K)?^b|D
0- UeFy
"v1(f|a
private void processErrorCode(int nErrorCode) a}K+w7VY\
{ "!tB";n
System.err.println("Error Code : " + nErrorCode); #+;=ijyF
} .{-yveE
O5Lv:qAa
WFd2_oAT
//停止文件下载 t}7wRTG
public void siteStop() WGmCQE[/c
{ |DW'RopM
bStop = true; 1aE/_
for(int i=0;i<nStartPos.length;i++) 1Tq$E[
fileSplitterFetch.splitterStop(); ej;taKzj
dx}/#jMa
l8-jFeeMd
} O[y`'z;C
} 2M?lgh4"
//负责部分文件的抓取 Z?.*.<"Sj
**FileSplitterFetch.java hYn'uL^~[
*/ WDdi}i>2
package NetFox; tZ^;{sM
/wE_eK.
!5j3gr~
import java.io.*; aS vE
import java.net.*; $O'2oeM
<o+ 7U
p2vBj.*J
public class FileSplitterFetch extends Thread { lM,zTNu-z
\&5@yh
`M ygDG+u
String sURL; //File URL Wk?|BR]O
long nStartPos; //File Snippet Start Position {*;]I?9Al
long nEndPos; //File Snippet End Position 0>=)
int nThreadID; //Thread's ID "t:.mA<v
boolean bDownOver = false; //Downing is over <IyLLQ+v
boolean bStop = false; //Stop identical tR*W-%
FileAccessI fileAccessI = null; //File Access interface d7J[.^\
;jU-<
.)>/!|i
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException S}^s5ztm
{ =t$mbI
this.sURL = sURL; }Tr83B|
this.nStartPos = nStart; _qt;{,t
this.nEndPos = nEnd; ^HFU@/
nThreadID = id; i @9Qb
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ; axaZV
} P}9Y8$Y>U
urXb!e{l
E#$_uZ4
public void run() $Kz\ h#}
{ ./nYXREO|
while(nStartPos < nEndPos && !bStop) @MZ6E$I
{ 7e4tUAiuU
2${,%8"0s
I^O:5x>[l
try{ }gi1?a59
URL url = new URL(sURL); K-5"#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _jrA?pY
httpConnection.setRequestProperty("User-Agent","NetFox"); /-{O\7-D
String sProperty = "bytes="+nStartPos+"-"; ]2\2/~l
httpConnection.setRequestProperty("RANGE",sProperty); qa$[L@h>
Utility.log(sProperty); 7 Mki?EG
B#GZmv1
~I\r1Wj;
InputStream input = httpConnection.getInputStream(); 0|s$vqc
//logResponseHead(httpConnection); |t65#1
L2>?m`wp
ccN&h
byte[] b = new byte[1024]; ;8L+_YCa
int nRead; h`EH~W0:z
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _WDBG
{ i. u15$
nStartPos += fileAccessI.write(b,0,nRead); UQ$\ an'
//if(nThreadID == 1) 1Fvv/Tj
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lYZ@a4TA
} /R(U>pZ
*]:G7SW{
@8M'<tr<z
Utility.log("Thread " + nThreadID + " is over!"); >|_gT%]5
bDownOver = true; ;H y!0n
//nPos = fileAccessI.write (b,0,nRead); F`;TU"pDf
} Ng."+&
catch(Exception e){e.printStackTrace ();} ^C:{z)"h
} 0l(E!d8&'
} Q_dXRBv=n
3)C6OF>7
lk*0c{_L
//打印回应的头信息 |%:qhs,
public void logResponseHead(HttpURLConnection con) gQI(=in
{ C NzSBm
for(int i=1;;i++) hpqHllL
{ m0BG9~p|
String header=con.getHeaderFieldKey(i); _cxm}*}\#
if(header!=null) x;ERRK
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }"&n[/8~
Utility.log(header+" : "+con.getHeaderField(header)); (b`4&sQ<
else {hvQ<7b
break; c6?c>*z
} 8"?Vcw&
} .fLiXx
RR~sEUCo{
Eo7 _v
public void splitterStop() zH=/.31Q
{ PEX26==
bStop = true; ,yHzo
} |z!q r}i
1kvPiV=X>
(1kn):
} 12:h49AP
.KiPNTh'
Pg*?[^*
/* "%.|n|
**FileAccess.java IL+#ynC
*//文件访问(定位，写) w2uRN?
package NetFox; 9D{u,Q V
import java.io.*; (!3Yc:~RE
~4MtDf
;1{iF2jZ:
public class FileAccessI implements Serializable{ D+ah ok
I<D&,LFH*w
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "xe7Dl
RandomAccessFile oSavedFile; dp"<KcP_
long nPos; Eonq'Re$
LKK{j,g7
AI^AK0.L
public FileAccessI() throws IOException RJtixuvh@
{ tl{]gz
this("",0); -,K*~z.l
} Ek"YM[
u4Y6B ]Q
qO:U]\P
public FileAccessI(String sName,long nPos) throws IOException otWo^CE$
{ Qq`3S>
oSavedFile = new RandomAccessFile(sName,"rw"); fap|SMGt
this.nPos = nPos; 8eOl@}bV
oSavedFile.seek(nPos); i>ESEmb-
} 17V\2=Io
4'+d"Ok
paq8L{R
public synchronized int write(byte[] b,int nStart,int nLen) SjZd0H0
{ q Axf5
int n = -1; K:}h\ In
try{ KcIc'G 9
oSavedFile.write(b,nStart,nLen); $x;tSJ)m~
n = nLen; t!6\7Vm/
} tpv?`(DDU
catch(IOException e) q1N4X7<_
{ Nbgp_:{
e.printStackTrace (); 3mpP|b"
} C$KaT3I
)v${&H
!d:tIu{)
return n; 'bLP~
} )vO_sIbnW
P/FrE~
f?2zLE>u
} cj$,ob&DX
re7!p(W?,
6tOP}X
/* |C~Sr#6)7
**SiteInfoBean.java 5\uNEs$T
*/ aF D="Zh
package NetFox; qv.[k<~a>
S/a/1n$ U
I|$'Q$m~
public class SiteInfoBean { xg(<oDn+\
R|/Wz/$1A
8r2XGR
private String sSiteURL; //Site's URL 5kK=S
private String sFilePath; //Saved File's Path q A.+U:I8
private String sFileName; //Saved File's Name Us1@\|]
private int nSplitter; //Count of Splited Downloading File 4#TnXxL
Sq?,C&LsA
w(aUEWYL
public SiteInfoBean() 4DvdEt
{//nSplitter的缺省值为5 >r~0SMQr
//default value of nSplitter is 5 <inl{CX/
this("","","",5); *^n^nnCwp
} 55LgBD
{PL,VY)Z
_wMc*kjJO
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) fv:L\N1u
{ yxqTm%?y
sSiteURL= sURL; A8J?A#R*{q
sFilePath = sPath; TV<Aj"xw
sFileName = sName; TV? ^c?{5
this.nSplitter = nSpiltter; cS4xe(n8
"pYe-_"@
'=$TyiU
} 7Ez}k}aR<
m^z,,t9
6{L F-`S%
public String getSSiteURL() 2ed@HJu
{ OO$|9`a
return sSiteURL; T)`gm{T
} \Ph]*%
n>n"{!
gEE9/\>%-
public void setSSiteURL(String value) se!g4XEWD
{ /=bSt
sSiteURL = value; 9wzwY[{
} [@g~
qv.n99?]
(s&ORoVGn
public String getSFilePath() Dp^95V@
{ _'&k#Q
return sFilePath; R!9qQn?
} 1p~5h(jI
$]Jf0_
YjX*)Q_sl?
public void setSFilePath(String value) Mg+4huT
{ )t5;d
sFilePath = value; _$!`VA%
} t]4!{~,
_g65pxt =Z
;e2Ij
public String getSFileName() Y4`QK+~fH
{ 'g2vX&=$A
return sFileName; `6UtxJSx
} FQ1arUOFW,
IOX:yxj
>C:If0S4X
public void setSFileName(String value) Q]^Yi1PbS
{ URLk9PI
sFileName = value; 9]Lo
} /;7ID41
RU7!U mf
n?}5!
public int getNSplitter() Qd?CTYNsv
{ ,b4g.CV
return nSplitter; Q4=|@|U0
} j6HR&vIM
/-><k,mL?
t|<FA#
public void setNSplitter(int nCount) vn``0!FX
{ %/Bvy*X&
nSplitter = nCount; &/iFnYVhy
} {!MVc<G.
} XO%~6Us^
B2Qp}
g1ytT%]
/* !D7"=G}HD
**Utility.java uS&LG#a
*/ @R UP$
package NetFox; ![).zi+m
W~<m[#:6C
%2}C'MqS
public class Utility { Fav^^vf*1
`On3/gU|
9{$8\E9*nd
public Utility() UP]1(S?
{ Qww^P/vm
P2t_T'R}
`\ R{5TU
} aLYLd/ KV
e62y
//线程睡眠 o)p[ C
public static void sleep(int nSecond) 0 7\02f
{ Co[n--@C
try{ "9ue76
Thread.sleep(nSecond); VVFV8T4
} c_Tzyh7l4
catch(Exception e) K\aAM;)-
{ E23w *']
e.printStackTrace (); NocFvF7\
} ZtR&wk
} u1N1n;#
0E1=W6UZ
//日志 p/3BD&6
public static void log(String sMsg) @701S(0'7
{ R:f7LRF/\
System.err.println(sMsg); _YLUS$Zw
} :/i~y$t
~z`/9;
Dkw*Je#6PX
public static void log(int sMsg) ED/FlL{
{ Oy%Im8.-A#
System.err.println(sMsg); r:NH6tAL
} (AuPZ
} Zih ?Bm
[;FofuZ
g|4w8ry
/* oq. r\r
**TestMethod.java L+t[&1cW
*/ '?8Tx&}U8
package NetFox; h0lu!m#\_
Um\0i;7 ~4
(6clq:c7j
public class TestMethod { 6__K#r
r0{]5JZt/
akCIa'>t
public TestMethod() |xeE3,8
{ ///xx/weblogic60b2_win.exe JGgxAd{L
try{ GS4_jvD-
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); n_9x"m$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [e1L{_*l
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8lb-}=
fileFetch.start(); ESv:1o`?n
} SK-W%t
catch(Exception e){e.printStackTrace ();} D%gGRA
!+KhFC&Py
H`el#tt_
} t!~S9c
o|rzN\WJn
:1MMa6
public static void main(String[] args) %E.S[cf%8&
{ gl "_:atW
new TestMethod(); HTR1)b
} hy!6g n
} IT&i,`cJ~F
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