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)); .v/s9'lB
} ~ 9^1m
for(int i=0;i<nEndPos.length-1;i++) !@W1d|{lu
{ ~BDVmQa
nEndPos = nStartPos[i+1]; 8QXxRD;0:
} UfOF's_'<
nEndPos[nEndPos.length-1] = nFileLength; B9>3xxp(by
} z )a8 ^]`
} ]y2(ZTNTs
?VCb@&*
]Tx8ImD#)A
//启动子线程 VbKky1a@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; mxGa\{D#y
for(int i=0;i<nStartPos.length;i++) vd9l1"S
{ `~(KbH=]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;rV0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [^8*9?i4
nStartPos,nEndPos,i); tceQn ^|<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6^if%62l&
fileSplitterFetch.start(); *&% kkbA
} 8ooj)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9"I/jd0B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); eH(8T
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", C-@@`EP
nEndPos = " + nFileLength); P%ev8]2
// fileSplitterFetch[nPos.length-1].start(); #J\ 2/~
++5W_Ooep
)o SFHf
//等待子线程结束 =V/$&96Q
//int count = 0; : \:jIP
//是否结束while循环 O<)"kj 7
boolean breakWhile = false; Z>wg o@z%
<6Y o%xt
ppM d
while(!bStop) 4 "@BbVYR
{ .%M=dL>
write_nPos(); %)i?\(/
Utility.sleep(500); RI')iz?
breakWhile = true; vaxNF%^~yN
_$9<N5F.,o
=L#tSa=M"
for(int i=0;i<nStartPos.length;i++) <DvpqlT
{ ,}=x8Xxr
if(!fileSplitterFetch.bDownOver) )67Kd]
{ BBnj}XP*4
breakWhile = false; /IxMRi=
break; 4["$}O5
} qg 4:Vq
} z%hB=V!~91
if(breakWhile) ;v[F@O~*)
break; TMhUo#`I|
E;@`{ v
B=(m;A#G
//count++; lw\OsB$
//if(count>4) ;E,%\<
// siteStop(); H/|Mq#K
} ${8 1~
k =ru) _$2
z%}^9
System.err.println("文件下载结束！"); (fUXJ$
} cZe,l1$
catch(Exception e){e.printStackTrace ();} :y"Zc1_E
} j\P47q'v#
w3:Y]F.ot
_WVeb}
//获得文件长度 Ja4O*C<
public long getFileSize() NFDi2L>Ba
{ Y`uL4)hR5
int nFileLength = -1; A%Pjg1(uX
try{ vnw83a%3
URL url = new URL(siteInfoBean.getSSiteURL()); g|9'Lk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R.Ao%VT
httpConnection.setRequestProperty("User-Agent","NetFox"); 2~<?E`+
9F(<n
2ZNTj u7h
int responseCode=httpConnection.getResponseCode(); ^+Ie
if(responseCode>=400) Sl/[9-a)
{ Dr^#e
processErrorCode(responseCode); +#"CgZ]
return -2; //-2 represent access is error 'ZgrN14
} +Tf,2?O
:tu6'X\k
=nh/w#
String sHeader; &y[Od{=
j="{^b
1[ ME/r
for(int i=1;;i++) po}Jwx!
{ HpiP"Sl
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); C:"Al-
//Utility.log(in.readLine()); y[UTuFv~Q
sHeader=httpConnection.getHeaderFieldKey(i); npkE[JE:
if(sHeader!=null) yEJ}!/
{ I8d#AVF2
if(sHeader.equals("Content-Length")) <{Wsh#7}.
{ il(dVW
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); c`yLn%Of%
break; 9fp1*d
} [[}KCND
} QmvhmsDL
else ArDkJ`DE
break; vrXUS9i.
} %G1kkcdH<
} B<SuNbR
catch(IOException e){e.printStackTrace ();} )[|`-M~u
catch(Exception e){e.printStackTrace ();} g""1f%U_p
g)u ~GA*=
iq)4/3"6
Utility.log(nFileLength); y/Fv4<X
6J9^:gXW~
<5?.s< y$"
return nFileLength; FX`SaY>D
} h|$.`$
Kr3L~4>
YDE;mIW
//保存下载信息（文件指针位置） M.O3QKU4
private void write_nPos() l~kxt2&
{ (, Il>cR4
try{ .uG|Vq1v
output = new DataOutputStream(new FileOutputStream(tmpFile)); 494"-F6
output.writeInt(nStartPos.length); d[;Sn:B
for(int i=0;i<nStartPos.length;i++) w[~O@:`]<o
{ J+r\EN^9
// output.writeLong(nPos); 3qR%Mf'
output.writeLong(fileSplitterFetch.nStartPos); y, @I6
output.writeLong(fileSplitterFetch.nEndPos); ?xu5/r<
} rH"&
output.close(); $TyV< G
} S 'S|k7Lp
catch(IOException e){e.printStackTrace ();} Lt$LXE
catch(Exception e){e.printStackTrace ();} `?+lM
} (%=[J/F/
I?}YS-2
0"]N9N;/
//读取保存的下载信息（文件指针位置） 8XZS BR(Z
private void read_nPos() PzbLbH8A
{ *^e06xc:
try{ ^"WrE(3
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); d%FD=wm
int nCount = input.readInt(); Pb4%"9`
nStartPos = new long[nCount]; dY'/\dJ
nEndPos = new long[nCount]; ,_?P[~1
for(int i=0;i<nStartPos.length;i++) {gT2G*Ed^Z
{ ^iAOz-H
nStartPos = input.readLong(); pT\>kqmj
nEndPos = input.readLong(); \yP\@cpY{
} ,)^4H>~V
input.close(); OBp<A+a
} BO)K=gl;8
catch(IOException e){e.printStackTrace ();} |giV<Sj
catch(Exception e){e.printStackTrace ();} $a|C/s+}7>
} LxaR1E(Cc'
qOAK`{b
Qxr&zT7f
private void processErrorCode(int nErrorCode) T|RW-i3
{ w7aC=B/{?i
System.err.println("Error Code : " + nErrorCode); <2@V$$Qg.~
} <3i2(k
;/T=ctIs
N) D;)ZH
//停止文件下载 n\Y{?x
public void siteStop() r!A1Sfo4P
{ P/uk]5H^
bStop = true; OIPJN8V
for(int i=0;i<nStartPos.length;i++) ]w ^9qS
fileSplitterFetch.splitterStop(); 8D7=]
',`GdfAsH
Y~@@{zP
} d;1%Ei3K
} z2p@d1
//负责部分文件的抓取 Al&)8x{p
**FileSplitterFetch.java qXC>DGy
*/ &}%rZU
package NetFox; >S/m(98
OtK=UtVI
>(nb8T|
import java.io.*; S-@E
import java.net.*; >Wvb!8N
91Bl{
w;f$oT
public class FileSplitterFetch extends Thread { e lj]e
hn]><kaA
DMO8~5
String sURL; //File URL NbG`v@yH
long nStartPos; //File Snippet Start Position \0. c_
long nEndPos; //File Snippet End Position F#d`nZ=M
int nThreadID; //Thread's ID !U,W; R
boolean bDownOver = false; //Downing is over -;rr! cQ?
boolean bStop = false; //Stop identical hS(}<B{x!
FileAccessI fileAccessI = null; //File Access interface (prqo1e@
:2^j/
6yZ!K
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException mhTi{t_fHM
{ DLMM1 A
this.sURL = sURL; rZ}y'A
this.nStartPos = nStart; (`%$Aa9J
this.nEndPos = nEnd; c!#DD;<Q
nThreadID = id; rfj>/?8!@
fileAccessI = new FileAccessI(sName,nStartPos);//定位 i%RN0UO^
} mFoE2?Y
=^
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public void run() !\D[lh}rL
{ ;oL`fQyr
while(nStartPos < nEndPos && !bStop) 0Bbno9Yp
{ 6%N.'wf
.C$4jR.KC
<*O~?=6p
try{ QAs$fi}f]s
URL url = new URL(sURL); iBlZw%zKP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G+Gd;`4
httpConnection.setRequestProperty("User-Agent","NetFox"); -n.ltgW@
String sProperty = "bytes="+nStartPos+"-"; u!wR
httpConnection.setRequestProperty("RANGE",sProperty); 9a4Xf%!F>z
Utility.log(sProperty); doeYc
Ci{,e%
GI:J9TS
InputStream input = httpConnection.getInputStream(); ~{-zj
//logResponseHead(httpConnection); C9+`sFau@
`+Ko{rf+9
+\r=/""DW
byte[] b = new byte[1024]; 4@|"1D3
int nRead; JQSp2b@'H
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) k.UQT^.
{ dw6U}
nStartPos += fileAccessI.write(b,0,nRead); NFDh!HUm
//if(nThreadID == 1) 1$1s0yg
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $A>\I3B
} 7Q_AZR4
~o"VZp
0xv@l^B
Utility.log("Thread " + nThreadID + " is over!"); !aylrJJ
bDownOver = true; u7L!&/6On
//nPos = fileAccessI.write (b,0,nRead); >\J({/ #O
} O+ ].'
catch(Exception e){e.printStackTrace ();} Pr|:nJs
} oaxCcB=\
} k{M4.a[(
?f}lYQzM
POZ5W)F(
//打印回应的头信息 W ='c+3O6
public void logResponseHead(HttpURLConnection con) ;S,k U{F
{ {& Pk$Q!
for(int i=1;;i++) #ZFedK0vv
{ ]I pLF#
String header=con.getHeaderFieldKey(i); Y`secUg
if(header!=null) 3}U {~l!K
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }a=<Gl|I;w
Utility.log(header+" : "+con.getHeaderField(header)); #2&DDy)Bf
else M}jF-z
break; f8Z[prfP
} V_)G=#6Dy
} (+M]C]
>j&+mii
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public void splitterStop() 6I5,PB
{ H83Gx;
bStop = true; *OoM[wEY
} \U(;%V
.Oh4b5
Etv!:\\[
} B;[ai?@c(_
-eZ$wn![
>a6{y
/* ape\zZCV
**FileAccess.java =IbDGw(
*//文件访问(定位，写) `>.^/SGu>?
package NetFox; !|\$|m<n
import java.io.*; rGNYu\\
0[\^Y<ec
H]^hEQ3DT
public class FileAccessI implements Serializable{ w+,Kpb<x[0
,RP"m#l!\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 QJeL&mf
RandomAccessFile oSavedFile; '>8IOC
long nPos; _zuaImJ0o
`a$c6^a
. 5cL+G1k#
public FileAccessI() throws IOException )sONfn
{ uItzFX*
this("",0); .mr&zq
} J(0E'o{ug
D9hV`fA
%MA o<,ha
public FileAccessI(String sName,long nPos) throws IOException 5X4 #T&.
{ >#9f{
oSavedFile = new RandomAccessFile(sName,"rw"); mNc?`G_R
this.nPos = nPos; [2WJ];FJ
oSavedFile.seek(nPos); {~L{FG)O
} XBvJc'(s
8Uv2p{ <#
@ )bCh(u
public synchronized int write(byte[] b,int nStart,int nLen) D90.z"N\i9
{ {c(@u6l28
int n = -1; xZMQ+OW2i
try{ ( o(,;
oSavedFile.write(b,nStart,nLen); }jfOs(Q]
n = nLen; xOKLc!J
} ]U4)2s
catch(IOException e) x6h';W_ 8
{ @pV~Q2%
e.printStackTrace (); QsXy(w#F
} 4@qHS0$
*VP-fyJp
sf7~hN*
return n; Fj_6jsDb
} )U2cS\k'7n
H}ie D"T_
x/<eY<Vgm?
} -2D/RE7|
GBh$nVn$
nfj8z@!
/* 5]c\{G
**SiteInfoBean.java 5.IX
*/ >TKl`O
package NetFox; vzXfJP
t)p. $
\f!j9O9S
public class SiteInfoBean { 006qj.
6bE~m<B\`
D ,U#z
private String sSiteURL; //Site's URL , z-#B]
private String sFilePath; //Saved File's Path 9"g!J|+
private String sFileName; //Saved File's Name (yr<B_Y'MY
private int nSplitter; //Count of Splited Downloading File O ,9,=2j
)R+26wZ|n*
}ldOxJSB?
public SiteInfoBean() ;2&ym)`
{//nSplitter的缺省值为5 N=vb*3ECg
//default value of nSplitter is 5 _nn\O3TB
this("","","",5); 0%W0vTvL
} Q>%{Dn\?
r;7&U<j~Z
]ChGi[B~9
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]%Db%A
{ :`Z'vRj
sSiteURL= sURL; m9Pzy^g1
sFilePath = sPath; ,f[`C-\Q%
sFileName = sName; 3*v&6/K
this.nSplitter = nSpiltter; Gg,&~ jHib
mw!EDJ;'
c}-WK*v
} EqYBT
2[V9`r8*
qQ{i2D%)?f
public String getSSiteURL() 5McOSy
{ U65a_dakk
return sSiteURL; *"HA=-Z;
} > &VY
[YTOrN
N!Q~?/!d
public void setSSiteURL(String value) g[%iVZ
{ !vY5X2?tr,
sSiteURL = value; `Lr I^9Z
} _!K@(dl
Qt~QJJN?oF
&*\-4)Tf
public String getSFilePath() 'CfM'f3uu
{ `pJWZ:3
return sFilePath; B/^1uPTZ71
} wBJP8wES=
LJh^-FQ
Y+ Qm.
public void setSFilePath(String value) 4k]DktY}.
{ V."qxKsz
sFilePath = value; z0F'zN3J
} ;,2;J3,pA
D8O&`!mf
aGx[?}=
public String getSFileName() }rKKIF^f\S
{ .B?J@,
return sFileName; ~USU\dni
} 9^zA(
oScKL#Hu
tB<2mjg
public void setSFileName(String value) v-MrurQ4
{ d^:(-2l-
sFileName = value; ?AlTQL~c
} )*m#RqLQ8
bpaS(nBy
7,!$lT#
public int getNSplitter() C%ZSsp u
{ |EpL~G_
return nSplitter; abczW[\
} RHj<t");
&f"kWOe$X
km=d'VvnI
public void setNSplitter(int nCount) Eo@b)h
{ CW . O"_
nSplitter = nCount; 79y'PFSms
} b'mp$lt!
} [CAV"u)0
wQR0R~|M
rl0|)j
/* NNTUl$
**Utility.java ,^m;[Dl7
*/ \1H~u,a
package NetFox; IS[&V&.n
-+H?0XN
"l7))>lL
public class Utility { dp=#|!jc
+}Q@{@5w
Lk8NjK6
public Utility() e<E]8GAF
{ AfqthI$*m
H]a@"gO
rD*CLqK
} ,f3Ck*M
=(\xe| Q
//线程睡眠 ](tv`1A,Wd
public static void sleep(int nSecond) ecqL;_{o
{ 1^R:[L4R`
try{ OLh QS_D
Thread.sleep(nSecond); lE 09Y
} fo5+3iu^
catch(Exception e) 7TaHE
{ Hp1n*0%dZ&
e.printStackTrace (); F =Zc_
} \66j4?H#
} 0<4Swj3s7
snccDuS
//日志 dZi?Z
public static void log(String sMsg) +1(L5Do}
{ :,*{,^2q:
System.err.println(sMsg); Tu9[byfrI
} lRr={ >s
YLAGTH0.]
]$xN`O4W{
public static void log(int sMsg) *(*3/P4D
{ `a:L%Ex
System.err.println(sMsg); dxwH C\"5
} jxdxIkAHZc
} 7O^'?L<C'
)gb gsQZ
N8K @ch3=P
/* P{{U
**TestMethod.java %J?"ZSh
*/ tiHP?N U
package NetFox; D$$,T.'u
lWe1Q#
.C7;T'>!
public class TestMethod { 25-5X3(>j=
|v?*}6:a
pQ/ bIuq
public TestMethod() #nS[]UbwZ
{ ///xx/weblogic60b2_win.exe 0*umf.R
try{ 1}>uY
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); M>kk"tyM
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); CDRkH)~$
SiteFileFetch fileFetch = new SiteFileFetch(bean); TexSUtx@$
fileFetch.start(); g#buy
} VfON{ 1g
catch(Exception e){e.printStackTrace ();} U%)m [zAw
* U#@M3g.
xOgUX6n
} @c{rqa v
V/@?KC0B5
,U?W
public static void main(String[] args) 6~b]RZe7
{ cV+x.)a.
new TestMethod(); w\f>.N
} kV$$GLD\
} Ohe*m[
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