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)); 9+9g(6
} yOz6a :r
for(int i=0;i<nEndPos.length-1;i++) '8)kFR^9
{ 8'@5X-nD
nEndPos = nStartPos[i+1]; 15J"iN2"W
} Y910\h@V
nEndPos[nEndPos.length-1] = nFileLength; yH"i5L9
} Szt2 "AR
} $$ *tK8#
^=^\=9" b
KJyCfMH&:@
//启动子线程 A{\?]]/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; X>`03?L
for(int i=0;i<nStartPos.length;i++) C)j/!+nh
{ QBGm)h?=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (8m_GfT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b}NNkM
nStartPos,nEndPos,i); NUVKAAgMX
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $)NS]wJ]3
fileSplitterFetch.start(); ~.3v\Q
} RN 4?]8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *_I`{9~'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %`k [xz
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", AR( gI]1
nEndPos = " + nFileLength); j"6|$Ze8
// fileSplitterFetch[nPos.length-1].start(); #b*4v&<
jC[_uG
Q(-&}cY
//等待子线程结束 8>WA5:]v
//int count = 0; 5QK%BiDlr
//是否结束while循环 &ox
boolean breakWhile = false; +pG+ xI
t[+bZUS$~
"9'3mmZm=?
while(!bStop) N{bg-%s10i
{ KE"6I
write_nPos(); 8<}=f4vUj5
Utility.sleep(500); AJ6l#j-
breakWhile = true; Kw"e4 a
rzHBop-8
rK'Lvt@w
for(int i=0;i<nStartPos.length;i++) b||usv[or
{ J:W+'x`@
if(!fileSplitterFetch.bDownOver) n[e C
{ ynM:]*~K
breakWhile = false; ./;uhj
break; QWa@?BO2p
} W8bp3JX"
} F8<G9#%s\
if(breakWhile) ByP<-Deh
break; !0hyp |F:>
\E,2VM@6
[ x+-N7
//count++; y'`7zJ
//if(count>4) .9e5@@VR
// siteStop(); !;8Y?c-D
} '8zd]U
eY#^vB
wipl5O@L
System.err.println("文件下载结束！"); R.WB.FP
} d #1&"(
catch(Exception e){e.printStackTrace ();} >)C7IQ/
} PcA^ jBgGl
9d|8c > I
8/j|=Q,5
//获得文件长度 ` Ny(S2
public long getFileSize() #*pB"L
{ 'kj q C
int nFileLength = -1; nG3SDL#(k
try{ ;/kd.Q
URL url = new URL(siteInfoBean.getSSiteURL()); B|a<=~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Dksn
httpConnection.setRequestProperty("User-Agent","NetFox"); Drtg7v{@\
OKm,iIp]
?bM%#x{e
int responseCode=httpConnection.getResponseCode(); Uf+y$n-
if(responseCode>=400) TYD( 6N
{ bC+ZR{M
processErrorCode(responseCode); #!z-)[S.+
return -2; //-2 represent access is error e0y.J
} Hy:x.'i
$+J39%Y!^
FVl, ttW
String sHeader; p@~Y[a =
7.VP7;jys
]tu OWR
for(int i=1;;i++) M887 Q'HSi
{ 1lIs jBo g
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); RQWUO^&e^
//Utility.log(in.readLine()); X%s5D&gr
sHeader=httpConnection.getHeaderFieldKey(i); Z*w({k7]
if(sHeader!=null) Zs/-/C|
{ 6_" n
if(sHeader.equals("Content-Length")) ]t!v`TH
{ <2@t~9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6R^F^<<
break; l-W)?d
} :I7qw0?
} [r>hKZU2
else "2%R?
break; D3aX\ NGP
} gzi=+oJ|4
} ?;](;n#lU
catch(IOException e){e.printStackTrace ();} >F^$ ' b]
catch(Exception e){e.printStackTrace ();} t)8crX}P
j%3$ytf|p
Tx&H1
Utility.log(nFileLength); S+KKGi_e
bj0HAgY@
32+N?[9 *
return nFileLength; fhZwYx&t
} ::02?
;p*L(8<YI
@=w)a
//保存下载信息（文件指针位置） "UD)3_R
private void write_nPos() 0y<9JvN$9
{ 9Oj b~
try{ ,9^ 5
output = new DataOutputStream(new FileOutputStream(tmpFile)); [wSoZBl
output.writeInt(nStartPos.length); U7fpaxc-
for(int i=0;i<nStartPos.length;i++) hb~d4J=S
{ =CFg~8W
// output.writeLong(nPos); *g}==o`
output.writeLong(fileSplitterFetch.nStartPos); Z\C"/j<y
output.writeLong(fileSplitterFetch.nEndPos); a9lYX*:
} Ke@Bf
output.close(); ]b}3f<
} < q(i(%
catch(IOException e){e.printStackTrace ();} RgFpc*.T
catch(Exception e){e.printStackTrace ();} l]DRJ
} Bz,D4E$
Us "G X_
IuPDr %
//读取保存的下载信息（文件指针位置） !^L}LtqHI
private void read_nPos() xF) .S@
{ BSy4 d>
try{ PNLlJlYlP
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 24InwR|^
int nCount = input.readInt(); OdyL j
nStartPos = new long[nCount]; FLPN#1
nEndPos = new long[nCount]; |#*+#27
for(int i=0;i<nStartPos.length;i++) O+XQP!T
{ oKSW:A
nStartPos = input.readLong(); $(J)F-DB i
nEndPos = input.readLong(); wAR:GO'n
} .wm<l:
input.close(); ZPM7R3%V)z
} T5pc%%q
catch(IOException e){e.printStackTrace ();} 2mj>,kS?c
catch(Exception e){e.printStackTrace ();} 4mBM5Tv
} UlN}SddI9
/Y\q&}
-{eiV0<^
private void processErrorCode(int nErrorCode) 7je1vNs
{ T;3~teVYB
System.err.println("Error Code : " + nErrorCode); )`5-rm~*
} vA*NJ%&`
ZQz;EV!
{XhpxJ__
//停止文件下载 )}w-;HX
public void siteStop() h*P0;V`UX
{ +f]I7e:qp
bStop = true; ?\Y7]_]/
for(int i=0;i<nStartPos.length;i++) 0x'Fi2=`
fileSplitterFetch.splitterStop(); V/OW=WCzN
R'K /\
~c1~)QzZ
} u_WW uo
} NFIFCy!
//负责部分文件的抓取 3kJSz-_M
**FileSplitterFetch.java T^xp2cZ
*/ H'EBe;ccM
package NetFox; OZObx
< R@&<E6
2(D&jL
import java.io.*; |@-y+vbA*
import java.net.*; Dhg/>@tw
Eh_[8:dK
nzYFa J+
public class FileSplitterFetch extends Thread { jaux:fU
dnPr2oI?I
~}~ yR*K%
String sURL; //File URL /s:akLBaD
long nStartPos; //File Snippet Start Position >273V+dy
long nEndPos; //File Snippet End Position g]}]/\
int nThreadID; //Thread's ID 1^;&?E
boolean bDownOver = false; //Downing is over <* PjG}Z.
boolean bStop = false; //Stop identical xi\uLu?i
FileAccessI fileAccessI = null; //File Access interface hi]\M)l&x
6B?1d /8V
0j/i):@
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /_bM~g
{ qn\>(&
this.sURL = sURL; GWShv\c}
this.nStartPos = nStart; Q;1$gImFz
this.nEndPos = nEnd; }Ty_} 6a5
nThreadID = id; DNM~/Oo
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1G8t=IA%D
} b;|^62
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:\1&5Pm]
public void run() 9Bmgz =8
{ JeCEj=_Z
while(nStartPos < nEndPos && !bStop) X_|} b[b
{ %^E>~
`[1]wV5(5@
[ 06B)|s
try{ r?2C%GI`
URL url = new URL(sURL); X4*/h$48 w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :Ws3+OI'm3
httpConnection.setRequestProperty("User-Agent","NetFox"); Nb{oH+$b
String sProperty = "bytes="+nStartPos+"-"; qm}7w3I^
httpConnection.setRequestProperty("RANGE",sProperty); 55|$Imnf
Utility.log(sProperty); g(;ejKSR
N=L urXv
}mJ)gK5b 6
InputStream input = httpConnection.getInputStream(); B "}GAk}V
//logResponseHead(httpConnection); I`KN8ll
9p$q@Bc
`^N;%[c`z
byte[] b = new byte[1024]; .g&BA15<F6
int nRead; E3KPJ`=!*"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,9M \`6
{ N4mQN90t
nStartPos += fileAccessI.write(b,0,nRead); aH$*Ue@Q
//if(nThreadID == 1) DwTZ<H4
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p-/x Md
} pV-.r-P
qC|re!K
aA yFu_
Utility.log("Thread " + nThreadID + " is over!"); ->#7_W
bDownOver = true; @o^sp|k !
//nPos = fileAccessI.write (b,0,nRead); AU$5"kBE
} %I=J8$B]f
catch(Exception e){e.printStackTrace ();} Y2D)$
} -s!PO;qm
} $fvUb_n
cE]kI,Fw,M
FRF}V@~
//打印回应的头信息 "Ii!)n,
public void logResponseHead(HttpURLConnection con) {S&&X&A`v
{ *AN#D?X_
for(int i=1;;i++) )*JTxMQ
{ \)"qN^we
String header=con.getHeaderFieldKey(i); ?%0i,p@<
if(header!=null) dX3>j{_
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %E!0,y,:
Utility.log(header+" : "+con.getHeaderField(header)); r#~6FpFVK^
else `4p9K
break; BzUx@,
} lJ,s}l7
} |O+binq
\%^3Izsc
LOYv%9$0*p
public void splitterStop() / q!&I
{ @<sP1`1
bStop = true; Z,&ywMm/G
} +[7u>RJ
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wLbnsqa
} Y{'G2)e
K=>/(sWiq
gy[uqm_ T
/* \ a<Ye T
**FileAccess.java 1wM p3
*//文件访问(定位，写) 1|89-Ii]
package NetFox; )G|UB8]
import java.io.*; Mt:(w;Y
`'QPe42
n#fg7d%
public class FileAccessI implements Serializable{ A|+{x4s`
8YJ({ Ou_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Y#5S;?bR
RandomAccessFile oSavedFile; ]_,~q@r$
long nPos; *]=)mM#
w{qYP
Vqr&)i"b$
public FileAccessI() throws IOException eyWwE%
{ DQ}]'*@?
this("",0); iB`m!g6$
} oAx0$]+%V)
WQ]pg "
] ge-b\
public FileAccessI(String sName,long nPos) throws IOException `F@yZ4L3S
{ M/qiA.C@W
oSavedFile = new RandomAccessFile(sName,"rw"); N@>S>U8C
this.nPos = nPos; EIfrZg7R
oSavedFile.seek(nPos); o_5@R+&
} L$Q+R'
1&<@(S<
VQ;=-95P
public synchronized int write(byte[] b,int nStart,int nLen) Xz@>sY>Jc
{ "8I4]'
int n = -1; ?~{xL"
try{ ^b#E%Rd
oSavedFile.write(b,nStart,nLen); ]=3O,\
n = nLen; J@fE")
} 4SrK]+|
catch(IOException e) ^s*} 0
{ )wRD
e.printStackTrace (); U8mu<)
} pf_ /jR
2^aTW`>L
>seB["C
return n; BSY#xe V
} m @%|Q;
wMoAvA_oS
@!da1jN
} +9J>'oe'D
^b~5zhY&
;~J~g#
/* _<7FR:oBZ
**SiteInfoBean.java #u$z-M !
*/ `vSsgG
package NetFox; ){:aGGtko
v(O.GhJ@
;=OH=+Rl
public class SiteInfoBean { 5PPpX=\
oX~CTunP
wW4S@m
private String sSiteURL; //Site's URL i]z i[Zo$
private String sFilePath; //Saved File's Path z"#.o^5
private String sFileName; //Saved File's Name !)=o,sVA
private int nSplitter; //Count of Splited Downloading File CmOb+:4@K
Ul Iw&U
+q$|6?
public SiteInfoBean() p rgjU
{//nSplitter的缺省值为5 3@L%#]xwi
//default value of nSplitter is 5 Cs{f'I
this("","","",5); h~p}08
} jHCKV
|_*$+
Kc0OLcu^d
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) vp@+wh]#
{ C.-a:oQ[
sSiteURL= sURL; o{p_s0IX;S
sFilePath = sPath; 3XtGi<u
sFileName = sName; @UJmbD{
this.nSplitter = nSpiltter; z sPuLn9G
)|x5#b-lz
lijy?:__
} cG:`Zj~4
d ] ;pG(
)[*O^bPowI
public String getSSiteURL() G m! ]
{ Tt|6N*b'
return sSiteURL; * U4:K@y
} sBnPS[Oo
beE%%C]X
K~-XDLh5Nu
public void setSSiteURL(String value) rR~X>+K
{ ~x:]ch|
sSiteURL = value; vM/v}6;_K2
} AtDrQ<>y'
$lA,{Q
)g_zPt
public String getSFilePath() ^E17_9?
{ ,IE0+!I
return sFilePath; ,v_r$kh^
} Y;Gm,
ASw|sw
':]a.yA\1
public void setSFilePath(String value) N-E`go
{ oFR'GUQC
sFilePath = value; +hgCk87%#
} <v k$eB8EC
Ai18]QD-
u$8MVP
public String getSFileName() Cl!jK^AbG
{ wtS*w
return sFileName; ,&]` b#Rc
} V JL;+
W2h[NimU
(t$/G3E
public void setSFileName(String value) cV,Dl`1r
{ Po.BcytM
sFileName = value; \r,.hUp
} &Ld8Z9IeFp
M) XQi/
m?$G(E5
public int getNSplitter() PSS/JFZ^
{ , vyx`wDd
return nSplitter; D(U3zXdO
} @(fY4]K
ilpZ/Rs
P%HyIODS
public void setNSplitter(int nCount) e~]e9-L>I
{ }yDq\5s Q[
nSplitter = nCount; v:1Vli.
} 9mphj)`d;#
} i!x5T%x_
9?chCO(@
"0zXpQi,B
/* n@[</E(
**Utility.java ]},Q`n>$
*/ kTc5KHJ7
package NetFox; 9XvM%aHs:
ULmdt
l(\8c><m
public class Utility { F6]!?@
1";e'?^x
{}&f\6OI%
public Utility() aw%vu
{ JO{- P
}SN44 di(
udI:]:,P
} [3sxzU!t~
`yXx[deY
//线程睡眠 U{uWk3I_b
public static void sleep(int nSecond) ss@}Dt^
{ r9a!,^}F
try{ Hs-.83V
Thread.sleep(nSecond); AnE_<sPA
} zn;Hs]G
catch(Exception e) pXj/6+^
{ ~K$"PKs3
e.printStackTrace (); fZ~kw*0*
} G[<[#$(
} $]U5
FoD/Q
//日志 h*%0@
public static void log(String sMsg) o7a6 )2JK
{ uC*:#[
System.err.println(sMsg); XvkI+c
} MD ?F1l"}%
pM'IQ3N
FDd>(!>
public static void log(int sMsg) 3auJ^B}
{ NuS|X
System.err.println(sMsg); {}J@+Zsi
} (06Vcqg
} ;ko[(eFN@
MLD>"W
"kBqY+:Cn
/* _QMHPRELk
**TestMethod.java _?]BVw
*/ fByh";<`P
package NetFox; l88a#zUQDN
&c<}++'h
@FdCbPl$
public class TestMethod { yK%GsCJd:
<X I35\^
4>"cc@8&~
public TestMethod() 4lh
{ ///xx/weblogic60b2_win.exe p-'6_\F.Ke
try{ NzeI/f3K5
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Y:"v=EhB
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]D) 'I`
SiteFileFetch fileFetch = new SiteFileFetch(bean); m!#)JFe67
fileFetch.start(); M$]O=2h+2
} Neo^C_[vN
catch(Exception e){e.printStackTrace ();} KIAe36.~
x#j\"$dla
Msa6yD#
} 4j/iG\
!G"9xrr1
s{z~Axup-
public static void main(String[] args) ~ S?-{X+
{ h\u0{!@}
new TestMethod(); qzHqj;
} .KU SNrs'
} n:bB$Ai2
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