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)); Pf5RlpL:p
} &2C6q04b
for(int i=0;i<nEndPos.length-1;i++) i% 19|an
{ n&Bolt(tO
nEndPos = nStartPos[i+1]; +h_'hz&HlS
} Me;@/;c(
nEndPos[nEndPos.length-1] = nFileLength; tz\7,yGT
} s7e)Mt
} {|= 8wB
Sh(
3&.?9
//启动子线程 mE^mQ [Dk
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6"U&i9
for(int i=0;i<nStartPos.length;i++) [0U!Y/?6lA
{ ;A7HEx
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ymkk"y.w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <yz)iCU?
nStartPos,nEndPos,i); hG .>>
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xjB2?:/2
fileSplitterFetch.start(); _doX&*9u
} dIgaw;Ch]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /_}xTP"9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); GzxtC&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", FZ'|z8Dm
nEndPos = " + nFileLength); <ek_n;R
// fileSplitterFetch[nPos.length-1].start(); *jM~VTXwt
aRPgo0,W1
yb*P&si5bY
//等待子线程结束 ]`)50\pdw
//int count = 0; Mk9'
//是否结束while循环 pt.0%3
boolean breakWhile = false; UhQ[|c
5 fY\0
JYB"\VV
while(!bStop) n=!]!'h\:
{ flDe*F^
write_nPos(); V1 T?T9m
Utility.sleep(500); (1p[K-J)r
breakWhile = true; (oO*|\9u
:c3}J<Z
Nv}'"V>
for(int i=0;i<nStartPos.length;i++) 58)`1p\c'
{ M>^Ho2
if(!fileSplitterFetch.bDownOver) {)nm {IV,
{ ykcW>h
breakWhile = false; 6!7LgM%4
break; Sd/?xyF1(
} d~@&*1}
} -jy-KC
if(breakWhile) rM<|<6(L
break; m-9{@kgAM?
EEFM1asJf
qXPjxTg{[
//count++; o5?f]Uq5 ,
//if(count>4) yk OJhd3
// siteStop(); ]Tk3@jw+b
} :#W40rUb
xp-.,^q\w
C9>tj=yEY
System.err.println("文件下载结束！"); Sn=|Q4ZN
} AB<|iJC
catch(Exception e){e.printStackTrace ();} ?Iy$'am]L
} _ #]uk&5a
^*(*tS|M
V)#se"GV
//获得文件长度 lj0"2@z3"E
public long getFileSize() 6p`AdDV
{ [mX/]31
int nFileLength = -1; 2>BWu
try{ )7@f{E#w
URL url = new URL(siteInfoBean.getSSiteURL()); Lt>"R! "x
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^]:w5\DG
httpConnection.setRequestProperty("User-Agent","NetFox"); LdxrS5
`F5iZWW1
.U|irDO
int responseCode=httpConnection.getResponseCode(); nI4Kuz`dF
if(responseCode>=400) =>nrU8x
{ ??eSGQ|
processErrorCode(responseCode); "`]G>,r_
return -2; //-2 represent access is error :ad
} +k|t[N
(n:d {bKV
_Kdqa%L !
String sHeader; :L gFd
6d/;GyG
AuIb>@a
for(int i=1;;i++) 3\_ae2GW
{ T(t@[U2^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); B1dVHz#
//Utility.log(in.readLine()); 7x`dEi<
sHeader=httpConnection.getHeaderFieldKey(i); ;|_aACina
if(sHeader!=null) 3aIP^I1
{ vf6_oX<Os
if(sHeader.equals("Content-Length")) j9"uxw@
{ e0iE6:i
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); kDJ$kv
break; wGdnv}#
} qW*JB4`?a
} BoQLjS{kN
else :xOne<@
break; I\djZG$s;N
} 1OB,UU"S$
} )yvI {
catch(IOException e){e.printStackTrace ();} c'M#va
catch(Exception e){e.printStackTrace ();} #x-@ >{1k&
u!I Es
sXHrCU
Utility.log(nFileLength); (IdXJvKU!
EC(,-sz\Z
7u[U%yd
return nFileLength; cQ(zBf
} umPd+5i
Q;r9>E!
48;6C g
//保存下载信息（文件指针位置） rg Gm[SL*<
private void write_nPos() m(MPVY<X
{ [vMksHk4
try{ $|+q9o\
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ia_I~ U$
output.writeInt(nStartPos.length); .B2?%2S
for(int i=0;i<nStartPos.length;i++) Q72}V9I9
{ HKu? J
// output.writeLong(nPos); fZ8%Z
output.writeLong(fileSplitterFetch.nStartPos); ' >a(|
output.writeLong(fileSplitterFetch.nEndPos); { FVLH:{U^
} )I7~<$w
output.close(); 4C@ .X[r
} 3ZdheenK9
catch(IOException e){e.printStackTrace ();} b=nQi./f
catch(Exception e){e.printStackTrace ();} =`RogjbP
} #[ZF'9x
Ik[aiz
Ay?KE{Qs '
//读取保存的下载信息（文件指针位置） Uedzt
private void read_nPos() &o{=
{ 'Cw&9cL9w
try{ b[5$$_[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); UjCQ W:[
int nCount = input.readInt(); 6)<g%bH!
nStartPos = new long[nCount]; (-k`|X"
nEndPos = new long[nCount]; /.PjHTM<
for(int i=0;i<nStartPos.length;i++) Gk~QgD/Pix
{ p4l^b[p
nStartPos = input.readLong(); %eJolztKZ
nEndPos = input.readLong(); ,H6*9!Dv2
} 6z;C~_BV
input.close(); :[icd2JCw]
} ,w>WuRN"
catch(IOException e){e.printStackTrace ();} Td!@i[6%H
catch(Exception e){e.printStackTrace ();} kb"g
} "},0Cs
pkWJb!
l!r2[T]I@7
private void processErrorCode(int nErrorCode) b6KO_s:'g
{ SvR:tyF
System.err.println("Error Code : " + nErrorCode); B[XVTok
} =W+ h.?
/u hA\m(
%:61@<
//停止文件下载 tE&@U$0>o
public void siteStop() ""AP-7
{ BS-nny
bStop = true; w[`2t{^j
for(int i=0;i<nStartPos.length;i++) Po+I!TL'
fileSplitterFetch.splitterStop(); #<_gY
sK1YmB :~a
5Q_T=TL
} QGv$~A[h
} h7],/? s
//负责部分文件的抓取 .KzGb4U
**FileSplitterFetch.java Af*e:}}
*/ =E{e|(1+u
package NetFox; NBLiwL37{
W lDcKY
sZ~q|}D-
import java.io.*; LW+a-i
import java.net.*; RM^3Snd=V
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E0F8FR'
public class FileSplitterFetch extends Thread { P''5A6#5
:.;pRz
4<`Qyul-
String sURL; //File URL t(<^of:
long nStartPos; //File Snippet Start Position (~C_zG
long nEndPos; //File Snippet End Position c!,&]*h"k
int nThreadID; //Thread's ID R^_7B(
boolean bDownOver = false; //Downing is over q> ;u'3}
boolean bStop = false; //Stop identical l/=2P_8+Z
FileAccessI fileAccessI = null; //File Access interface x2-i1#j`;
G8]DK3#
/g|H?F0
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }>)e~\Tdzb
{ j=raS
this.sURL = sURL; o+9b%I^1V
this.nStartPos = nStart; %[1\d)
this.nEndPos = nEnd; Y}db<Cz X
nThreadID = id; 5|T[:m
fileAccessI = new FileAccessI(sName,nStartPos);//定位 RQaB_bg7
} KyQO>g{R
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public void run() (#|CL/&
{ z]/;?
while(nStartPos < nEndPos && !bStop) j41)X'MgJ
{ {zTo[i
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try{ ld RV JVZc
URL url = new URL(sURL); J[Ckz]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); " Bz\<e&u
httpConnection.setRequestProperty("User-Agent","NetFox"); +[LG>
String sProperty = "bytes="+nStartPos+"-"; U;o$=,_p
httpConnection.setRequestProperty("RANGE",sProperty); bn$('
Utility.log(sProperty); :v=^-&t
n*'i{P]
]4{ )VXod
InputStream input = httpConnection.getInputStream(); O)0}yF$0
//logResponseHead(httpConnection); @D?KS;#
=rw60B
E_fH,YJ?9
byte[] b = new byte[1024]; *=sMJY9#jE
int nRead; x,U'!F
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0_!')+
{ (d> M/x?W
nStartPos += fileAccessI.write(b,0,nRead); cRR[ci34k
//if(nThreadID == 1) ^Y;}GeA,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7WEh'(`
} kIC$ai6.
^M:Y$9r_s
zmA]@'j
Utility.log("Thread " + nThreadID + " is over!"); ~}lYp^~:J
bDownOver = true; ,M4G_U[
//nPos = fileAccessI.write (b,0,nRead); JJIlR{WY_
} -<g&U*/E
catch(Exception e){e.printStackTrace ();} i6S5 4&^!
} n!Dr:$
} u[{j;l(
&dH[lB
5Kadh2nz
//打印回应的头信息 & bKl(,
public void logResponseHead(HttpURLConnection con) \ F\ /<
{ e_<'zH_1
for(int i=1;;i++) W2$MH: j
{ O c[F
String header=con.getHeaderFieldKey(i); $ \yZ;Z:
if(header!=null) j_(DH2D
//responseHeaders.put(header,httpConnection.getHeaderField(header)); &["s/!O1R
Utility.log(header+" : "+con.getHeaderField(header)); }?\8%hK"a7
else Ipp#{'Do
break; P{bRRn4Z
} GiZv0>*x
} Mr0<b?I
<W>T!;4!
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public void splitterStop() 6-fdfU
{ pmWt7 }
bStop = true; +jEtu[ ;
} 9}[UZN6
tj'xjX
VRb+-T7"
} J1s~w`,
Jbv[Ql#
R&-Vm3mc3
/* &x":
**FileAccess.java ?Z0NHy;5
*//文件访问(定位，写) (&B`vgmb
package NetFox; vcmB)P-T`O
import java.io.*; /wR,P
iBM;$0Y
=O1py_m
public class FileAccessI implements Serializable{ W0I)< S
5LF&C0v
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 bQvhBa?
RandomAccessFile oSavedFile; D<QE?:#
long nPos; <dD)>Y.
r6b;v2!8
cXd?48O
public FileAccessI() throws IOException ee}HQ.}Ja
{ ? PI2X.6
this("",0); 8PB 8h
} FwjmC%iY
!RXG{1:
%w3Y!7+
public FileAccessI(String sName,long nPos) throws IOException 4:I'zR5
{ ^pysoaZCT_
oSavedFile = new RandomAccessFile(sName,"rw"); svaclkT=
this.nPos = nPos; *y0=sG1+D
oSavedFile.seek(nPos); TwI'}J|w
} F"ua`ercI
n^t!+
D}MCVNd^
public synchronized int write(byte[] b,int nStart,int nLen) Hrg~<-.La
{ S;8gX1Uf
int n = -1; W]CsKN,K
try{ ~Z>!SMXp<
oSavedFile.write(b,nStart,nLen); 6Mj(B*c
n = nLen; 4Zn"K}q
} Mb^E
catch(IOException e) ,J4rKGG
{ W\pO`FL
e.printStackTrace (); m<e_Z~^G
} ~PtIq.BY
@2;/-,4O
fP KFU
return n; bzWWW^kNL
} k9_c<TSzu
Ncr*F^J4
YAsE,M+
} =j~vL`d2]
TF%MO\!
;{Nc9d
/* |[W7&@hF
**SiteInfoBean.java ccY! OSae
*/ UOa n
package NetFox; :pCv!g2
P#l"`C /
MJM<
public class SiteInfoBean { *~\R0ddz
XQPlhpcv
U~GQ JR
private String sSiteURL; //Site's URL YHOo6syk
private String sFilePath; //Saved File's Path M~ku4ZP
private String sFileName; //Saved File's Name NiSH$MJ_
private int nSplitter; //Count of Splited Downloading File @~CXnc0
^1-Vd5g
iF*L-
public SiteInfoBean() fc<~R
{//nSplitter的缺省值为5 +pY--5t
//default value of nSplitter is 5 tyU'[LF?
this("","","",5); c0v6*O)
} mXOY,g2w
U}R(
K"/3/`T
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +GvPJI
{ x(+H1D\W
sSiteURL= sURL; bV&"jjEx
sFilePath = sPath; 6qd?&.=r
sFileName = sName; 'w8p[h (,
this.nSplitter = nSpiltter; VCX^D)[-
=$-+~
a797'{j#PI
} 2_GbK-
]ne
isU4D
public String getSSiteURL() Q*ixg$>
{ *TgD{>s
return sSiteURL; jdX*
} )wNcz~ Y
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&&ZX<wOM
public void setSSiteURL(String value) dCA! R"HD
{ X#k:J
sSiteURL = value; g`(3r
} Z 5 Xis"j
d:#z{V_
`t#9 yN
public String getSFilePath() 9UCA&n
{ %W^Zob
return sFilePath; uQYenCNXS
} ?UV|m
b ;>?m
Kz"&:&R"
public void setSFilePath(String value) r1BL?&X-
{ 9~{,Hj1xE
sFilePath = value; zG)vmysJf
} aen0XiB6~^
lkW5<s_
>o1,Y&
public String getSFileName() uvl>Z= "
{ 2j&0U!DX
return sFileName; 6xLQ
} wpg7xx!
Ot{~mMDp
5><T#0W?
public void setSFileName(String value) f0{j/+F_o
{ xri(j,mU
sFileName = value; k\X yR4r
} @rS(3wu_&
7U!-_)n{
#$;}-*
public int getNSplitter() ^/I.? :+
{ b(\Mi_J
return nSplitter; \ #N))gAQ
} ^p~QHS/
i`5Skr:M
p,BoiYdi
public void setNSplitter(int nCount) tYp 185
{ u\(>a
nSplitter = nCount; ]Pe8G(E!
} W~FU!C?]
} *|ef#-|D
1&RB=7.h
ioUO0
/* P4:Zy;$v!
**Utility.java 0),fY(D2T
*/ Fl!D2jnN
package NetFox; &88c@Ksn
2U3e!V
eV"s5X[$
public class Utility { ?)H:.]7-x
Sd/7#
vxS4YRb
public Utility() V n+a-v
{ A8g_BLj!e
qJE_4/<^!
Sx1|Oq]
} [ldBI3
QO:Z8{21So
//线程睡眠 [X7gP4
public static void sleep(int nSecond) ??f,(om
{ ZiPz~G0[^
try{ P(!%Pp
Thread.sleep(nSecond); dL~^C I
} r>gf&/Pl
catch(Exception e) ]cM8TT
{ MDBqIL]Hc
e.printStackTrace (); ~~@dbB
} _WZ{i,
} o]WcODJdl
y>cLG5v
//日志 #jsN
public static void log(String sMsg) 'e_e*.z3
{ 4X!4S6JfB
System.err.println(sMsg); tt|P-p-
} -qBdcbi|x)
-s0\4
> Edsanx
public static void log(int sMsg) 86>@.:d
{ 2f1Q&S
System.err.println(sMsg); r4d#;S9{o
} {|'NpV
} M9G?^mW1sT
%K,cGgp^)
bVzJOBe
/* 2Bi?^kQ#
**TestMethod.java @?RaU4e
*/ }$[@*
package NetFox; T\#Gc4
7yjun|Lt}X
I>q!co9n
public class TestMethod { H^dw=kS
J#5V>7G
hiv {A9a?
public TestMethod() _2{2Xb
{ ///xx/weblogic60b2_win.exe \Rs9B .
try{ SYh>FF"
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @urZ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !?>I
SiteFileFetch fileFetch = new SiteFileFetch(bean); L={\U3 __k
fileFetch.start(); wR,}#m,
} ' 6)Yf}I
catch(Exception e){e.printStackTrace ();} L c )i
>cpv4Pgm
$@l=FV_;
} yo8mfH_,
?op;#/Q(
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public static void main(String[] args) eSHsE3}h
{ {|<yZ,,p
new TestMethod(); 7rYBFSp
} =oM#]M'G+(
} =l:k($%%
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