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)); cBf9-k
} (Wkli:Lq
for(int i=0;i<nEndPos.length-1;i++) 9hAS#|vK
{ >Gbj1>C}
nEndPos = nStartPos[i+1]; xe^*\6Y
} 5,=Yi$x
nEndPos[nEndPos.length-1] = nFileLength; `@GqD
} RZ)sCR
} O+;0|4V%
Zu(eYH=Q
{zoUU
//启动子线程 ~ILig}I
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; u2HkAPhD
for(int i=0;i<nStartPos.length;i++) @rs(`4QEh
{ xsK{nM6g
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?fv?6r
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _'&N01
nStartPos,nEndPos,i); v+-f pl&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~82[pY
fileSplitterFetch.start(); _3$@s{k-TI
} t}-[^|)7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 51yIW*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); r})2-3ZA9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~XGO^P"?
nEndPos = " + nFileLength); h}xUZ:
// fileSplitterFetch[nPos.length-1].start(); j`^':!
H"(:6 `
d7N;Fa3yL
//等待子线程结束 XfA3Ez,}
//int count = 0; zM6yUEg
//是否结束while循环 3_=~7B) 8
boolean breakWhile = false; {ZFa +
$,08y
\V@SCA'
while(!bStop) *Yv"lB8
{ Mq) n=M
write_nPos(); R_h(Z{d
Utility.sleep(500); E [JXQ76
breakWhile = true; m1_?xU
N_<sCRd]9
/H.QGPr
for(int i=0;i<nStartPos.length;i++) >JT{~SRB|Y
{ U`q[5U"
if(!fileSplitterFetch.bDownOver) ^B@4 w\t
{ zjgK78!<
breakWhile = false; gd<8RVA
break; Wu)ATs}
} Sp)KtMV
} SCeZt [
if(breakWhile) RAKQ+Y"nl
break; ANSvZqKh
aKs!*uo0H
FtN1ZZ"<*
//count++; []Cvma1\
//if(count>4) 6h>8^l
// siteStop(); \Ekez~k{`
} Qu]0BVIe
z.16%@R
H%7V)"
System.err.println("文件下载结束！"); )hk=wu6
} g$VcT\X
catch(Exception e){e.printStackTrace ();} [rqe;00]
} qx 3.oU
k/l@P
4,9AoK)yp
//获得文件长度 =1^a/
public long getFileSize() ih`/1n
{ #%VprcEK
int nFileLength = -1; TUhp
try{ *pP"u::S
URL url = new URL(siteInfoBean.getSSiteURL()); 0kgK~\^,.O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YN] w_=
httpConnection.setRequestProperty("User-Agent","NetFox"); }7hpx!s,
j5z, l
*F:]mgg
int responseCode=httpConnection.getResponseCode(); 'R_U,9y`
if(responseCode>=400) D,xWc|V
{ qt]QO1pAd
processErrorCode(responseCode); v,vTRrpK
return -2; //-2 represent access is error 0!=e1_
} 3sGrX"0D
f[7'kv5S
o0-e,F>u
String sHeader; XBhWj\`(T
QOuy(GY
bI[!y#_z4
for(int i=1;;i++) N-^\X3X
{ V.WfP*~NJ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /6{`6(p
//Utility.log(in.readLine()); B2d$!Any
sHeader=httpConnection.getHeaderFieldKey(i); >0 !J]gK
if(sHeader!=null) 4\pA^%73
{ d1e'!y}R5
if(sHeader.equals("Content-Length")) w%S<N
{ 5K'EuI)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7i{Rn K6*
break; rQ}4\PTi
} qIjC-#a=m
} |L;'In
else :EgdV
break; N(vbo
} OpxVy _5,
} yD1*^~loJ
catch(IOException e){e.printStackTrace ();} 2DQ'h}BI
catch(Exception e){e.printStackTrace ();} yE9JMi0
6(9Ta'ywZ
lk.Q6saI1
Utility.log(nFileLength); F/j=rs,*|D
@PwEom`a
?]fBds=
return nFileLength; 7P/j\frW
} w2]1ftY
`RGZ-Q{_
';aPoaO %
//保存下载信息（文件指针位置） x(}tr27o
private void write_nPos() p5F[( H|9
{ ^%_B'X9
try{ 8YkP57Y%[Z
output = new DataOutputStream(new FileOutputStream(tmpFile)); 74gU4T
output.writeInt(nStartPos.length); H'gPGOd
for(int i=0;i<nStartPos.length;i++) lG#&Pv>-
{ K'?ab 0
// output.writeLong(nPos); |Q9S$l]
output.writeLong(fileSplitterFetch.nStartPos); 6FEtq,;0w
output.writeLong(fileSplitterFetch.nEndPos); /oiAAB27
} JS(KCY9
output.close(); YD@V2gK
} tB(Q-c
catch(IOException e){e.printStackTrace ();} @1n0<V/
catch(Exception e){e.printStackTrace ();} VPN@q<BV
} 7/Lbs
czMLvPXRx
bSz6O/A/
//读取保存的下载信息（文件指针位置） LV8,nTYvE
private void read_nPos() d,<ctd
{ !LIWoa[ F.
try{ t ?bq~!X
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /SMp`Q88
int nCount = input.readInt(); S\0"G*
nStartPos = new long[nCount]; :\80*[=;Z
nEndPos = new long[nCount]; yrsP'th
for(int i=0;i<nStartPos.length;i++) }GkEv}~t
{ nWXI*%m5
nStartPos = input.readLong(); :Hd?0eZ|
nEndPos = input.readLong(); CWBsiL f
} ,}{E+e5jh7
input.close(); ?'T>/<(
} $Fr2oSTT)
catch(IOException e){e.printStackTrace ();} M8juab%y
catch(Exception e){e.printStackTrace ();} rcI(6P<*
} ;uoH+`pf
.\U+`>4av
ybS7uo
private void processErrorCode(int nErrorCode) @.0jC=!l
{ #{h4lte
System.err.println("Error Code : " + nErrorCode); |{9"n<JW
} !]kn=7
+e?ixvld
yvH:U5%
//停止文件下载 K03a@:
public void siteStop() <S\S @3
{ Q;5\( 0w5
bStop = true; $oxPmELtpe
for(int i=0;i<nStartPos.length;i++) W:5m8aE\
fileSplitterFetch.splitterStop(); 3N]pN<3@
_&F6As !{
WO)K*c1F
} gVG :z_6
} p~3CXmUc~
//负责部分文件的抓取 ; $y.+5 q
**FileSplitterFetch.java R4IFl z
*/ xY!]eLZ)&
package NetFox; 3I"&Qp%2
h+Q==
k.lnG5e
import java.io.*; 2&tGJq-E
import java.net.*; u|QfCwQ
6eS#L21*
:=i0$k<E/
public class FileSplitterFetch extends Thread { t#P)KcWOt
2iH,U
.5dZaI)
String sURL; //File URL @Rx/]wyH
long nStartPos; //File Snippet Start Position {qx"/;3V
long nEndPos; //File Snippet End Position ,/d-o;W
int nThreadID; //Thread's ID KO5Q;H
boolean bDownOver = false; //Downing is over " g_\W
boolean bStop = false; //Stop identical CiMy_`H
FileAccessI fileAccessI = null; //File Access interface 3i s.c)
J|'T2g
o1n c.2/0J
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException B]Zsn`n
{ LG,RF:
this.sURL = sURL; e,4!/|H:
this.nStartPos = nStart; n:#ji|wM
this.nEndPos = nEnd; Xp{gh@#dr
nThreadID = id; y!v$5wi
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @{nT4{
} +-.BF"}
1%-?e``.
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public void run() <4O=[Q5S
{ \DQ;v
while(nStartPos < nEndPos && !bStop) Jx{,x-I
{ X,OxvmDm
Z2$-},i
+pFz&)?
try{ <v2R6cj5
URL url = new URL(sURL); \\/X+4|o'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -_314j=`/
httpConnection.setRequestProperty("User-Agent","NetFox"); [0~qs|27
String sProperty = "bytes="+nStartPos+"-"; >K &b,o,[
httpConnection.setRequestProperty("RANGE",sProperty); '.dW>7
Utility.log(sProperty); t 1&p> v
ar^`r!ABEh
pixI&iQ
InputStream input = httpConnection.getInputStream(); P{qn@:
//logResponseHead(httpConnection); 7P\sn<
FcWu#}.p}
B[$SA-ZHi
byte[] b = new byte[1024]; Lte\;Se.tu
int nRead; ';lO[B
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }>OE"#si
{ Hv`Zc*
nStartPos += fileAccessI.write(b,0,nRead); M0"feq
//if(nThreadID == 1) lO) B/N&
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m#SZI}
} ~]yqJYiid^
my} P\r.
L`Ic0}|lzy
Utility.log("Thread " + nThreadID + " is over!"); Z7f~|}
bDownOver = true; t)m4"p7
//nPos = fileAccessI.write (b,0,nRead); 8ziYav
} bZlAK)
catch(Exception e){e.printStackTrace ();} !PQRlgcG
} z[k2&=c
} D=OU61AA
$`5DGy?RU
_E"[%
//打印回应的头信息 I3L1|!
public void logResponseHead(HttpURLConnection con) x[?_F
{ wXZ-%,R-D
for(int i=1;;i++) ::5-UxGL<2
{ P#0_
String header=con.getHeaderFieldKey(i); FE5R ^W#u-
if(header!=null) y%GV9
//responseHeaders.put(header,httpConnection.getHeaderField(header)); MUo?ajbqOd
Utility.log(header+" : "+con.getHeaderField(header)); <T}#>xHs3
else Vnl~AQfk|
break; #2MwmIeA
} h\dIp`H
} h!Q>h7
_AO0:&
lu{}j4
public void splitterStop() :#LB}=HQ
{ K)14v;@
bStop = true; <AIsNqr
} @2u<Bh}}
J)-owu;
kQb0pfYs
} QxkfP%_g
:C&?(HJ&r
q"cFw${
/* td m{ V st
**FileAccess.java ysa"f+/
*//文件访问(定位，写) 6RF01z|~_
package NetFox; ENmo^O#,u
import java.io.*; *dQRs6
nJ?C4\#3
a=J?[qrx
public class FileAccessI implements Serializable{ CVUDN2
A1@-;/H3
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -Rvxjy)[N
RandomAccessFile oSavedFile; .dfTv/n
long nPos; ::R^ w"
@N(jd($E
%MIu;u FR
public FileAccessI() throws IOException =MXF`k^}
{ r" D|1
this("",0); [0}471
} nFP2wvFM
P]TT
Brl6r8LGi
public FileAccessI(String sName,long nPos) throws IOException EvYw$j
{ <Kh\i'8
oSavedFile = new RandomAccessFile(sName,"rw"); 6M6QMg^
this.nPos = nPos; 4 hj2rK'y
oSavedFile.seek(nPos); VgdkCdWRm_
} ]`NbNr]K
*Z]| Z4Q/`
GWhZ Mj
public synchronized int write(byte[] b,int nStart,int nLen) i-<=nD&?t
{ (kHR$8GFM
int n = -1; -3V~YhG
try{ RpXQi*c0
oSavedFile.write(b,nStart,nLen); l=oVC6C
n = nLen; x B?:G
} -r2cK{Hhp&
catch(IOException e) 3x'30
{ V;6M[ic}
e.printStackTrace (); ~L1O\V i
} <Hp"ZCN
"VeUOdNA>
d5%*^nMpY
return n; (HF,p,h_
} epL[PL}
EH3G|3^xz
NWg\{a
} cjR.9bgn
SQ!lgm1bA
Mz^s^aJEE
/* >R:+ml
**SiteInfoBean.java %8tN$8P
*/ =4D_-Q
package NetFox; Dmi;# WY
;!}SgzSH}
pd1m/:
public class SiteInfoBean { YUb,5Y0
[w/t
7`/qL "
private String sSiteURL; //Site's URL acZHb[w
private String sFilePath; //Saved File's Path 9c^EoYpy-
private String sFileName; //Saved File's Name OgS8.wX
private int nSplitter; //Count of Splited Downloading File of`]LU:
"6dbRo5%
Zz-;jkX)
public SiteInfoBean() ."X~?Nk
{//nSplitter的缺省值为5 de6dLT>m
//default value of nSplitter is 5 nnNg^<[k3
this("","","",5); Sg$\ab$
} T/;hIX:R
$te,\$&}
\i+h P1mz
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,m?D\Pru
{ b1u'ukDP\
sSiteURL= sURL; E?mp6R]}%
sFilePath = sPath; Q75^7Ga_
sFileName = sName; ?<?C*W_
this.nSplitter = nSpiltter; KUutC :
+I n"OR%
g)A0PvEu
} fB96Q
mv.I.EL
V^z;^mdd
public String getSSiteURL() )T5h\ZO`;
{ ;"^9L
return sSiteURL; .^S78hr]n
} F\R}no5C
cOZ^huK
}hitU(5t0
public void setSSiteURL(String value) kA;Tr4EA6
{ T:">,*|
sSiteURL = value; Iq]6]
} Pu*HZW3l
8VmN?"5v
1!wEXH(
public String getSFilePath() &i^NStqu
{ yn[ZN-H~
return sFilePath; 2P_^@g
} $F7gH
~&lJT
WkySTc
public void setSFilePath(String value) %`'z^W
{ )xx/di
sFilePath = value; 50aWFJYw
} &jZ|@K?
Q3%# o+R>
h;p%EZ
public String getSFileName() |K;Txe_
{ %OW9cqL>l
return sFileName; Yb3f]4EH
} p}DF$k%`
xO-U]%oq
+7<>x-+
public void setSFileName(String value) ]MLLr'6?
{ y6Epi|8
sFileName = value; {dx /p-Tv
} 0o$HC86w
wv.Ulrpx.
s]vJUC,s
public int getNSplitter() Sje0:;;|
{ HL}~W}!j
return nSplitter; % rY8
} >^f)|0dn)E
.S'fM]_#
]|t.wr3AU
public void setNSplitter(int nCount) E:4P1,%01+
{ s!/holu
nSplitter = nCount; XH:gQ9FD
} if[o?6U4t
} 4_762Gu%
@Du}
Y`7#[g
/* #!Cter2
**Utility.java #G+
*/ -Bo~"q
package NetFox; hRa(<ZK
Eh@T W%9*
uWB:"&!^
public class Utility { 7{^4 x#NO
nN`Z0?
y^QYlZO
public Utility() PWk?8dL-
{ Wbn[Q2h5
ZE8/ m")
QPe9s[Y
} B>|U-[A
;*-@OLT_K
//线程睡眠 \l]pe|0EW
public static void sleep(int nSecond) : \:~y9X0
{ a()6bRc~T
try{ B221}t
Thread.sleep(nSecond); du'}+rC
} g{v5mly
catch(Exception e) ` -[Bo
{ H6ky)kF&
e.printStackTrace (); HZDaV&)@
} YQ@dl
} \)otu\3/
uRm_
//日志 >'ksXA4b
public static void log(String sMsg) Wj4^W<IO
{ !2Xr~u7a
System.err.println(sMsg); Oj"pj:fB
} !u53 3
{\svV 0)~
-7k|6"EwM
public static void log(int sMsg) K$<`4#i
{ 5%QC ][,
System.err.println(sMsg); 4+5OR&kxZ
} }$Hs;4|
} \[[TlB>
d=t}T6.|
sb}K%-
/* (ET ;LH3
**TestMethod.java @.Z[M
*/ +~w?Xw,
package NetFox; <V$Y6(uMs
:dY.D|j*
f@! fW&
public class TestMethod { i'W_;Y}
DJViy
"ep`
public TestMethod() ASKAgU"h
{ ///xx/weblogic60b2_win.exe X,WQ'|rC
try{ <JL\?)}n
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8h&oSOkQk,
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); YY#s=
SiteFileFetch fileFetch = new SiteFileFetch(bean); -E8ntY-
fileFetch.start(); 5\akI\
} r~$}G-g
catch(Exception e){e.printStackTrace ();} 7P/?wv9+n*
[$( sUc(%
4_Qa=T8
} y+4?U
]aC':55(
%[]"QbF?
public static void main(String[] args) oLrkOn/aY
{ xFBh?
new TestMethod(); @-wNrW$
} [&h#iTRT
} Io$w|~x
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