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)); >d 5-if
} Hav&vV
for(int i=0;i<nEndPos.length-1;i++) 7qC /a c
{ gS(3m_
nEndPos = nStartPos[i+1]; CL<-3y*
} '}cSBbl&/n
nEndPos[nEndPos.length-1] = nFileLength; :ez76oGyc
} $z=a+t *
} ~d*Q{v~3
Th_@'UDa
Agd"m4!
//启动子线程 p$,7qGST
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {O+T`;=)L
for(int i=0;i<nStartPos.length;i++) Laj/~Ru6
{ 1P)K@j
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pH~\~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %1&X+s3
nStartPos,nEndPos,i); G^'We6<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g;l K34{
fileSplitterFetch.start(); kNuvJ/St
} 6(rm%c
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8\J$\Edv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); l;-2hZ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ZayJllaq^
nEndPos = " + nFileLength); |Iy;_8c
// fileSplitterFetch[nPos.length-1].start(); {$S"Sj
!(*&P
m"L^tSD~
//等待子线程结束 LWrYKi
//int count = 0; ("`"?G
//是否结束while循环 d=1\=d/K
boolean breakWhile = false; :6n4i$
VgPlIIHh5
WUS%4LL(
while(!bStop) _'p/8K5)=
{ 0>[]Da}
write_nPos(); T m"B
Utility.sleep(500); b>5*G1
breakWhile = true; D;sG9Hky
0hY3vBQ!
4KH'S'eR
for(int i=0;i<nStartPos.length;i++) (-<hx~
{ wOH:'sk["
if(!fileSplitterFetch.bDownOver) Q g/Rw4[
{ x(?Rm,
breakWhile = false; E8C8kH]
break; mJ%^`mrI
} <*vR_?!
} F`KXG$
if(breakWhile) KKwM\
break; u?V}pYX
@@ j\OR
1_7p`Gxt[/
//count++; 2K4Xu9-i:b
//if(count>4) 0MpW!|E[b
// siteStop(); B9l~Y/3|
} -axKnfj
auI`'O`/
\LUW?@gLa
System.err.println("文件下载结束！"); .QY>@b\
} 7<LuL
catch(Exception e){e.printStackTrace ();} E2|M#Y
} Av.`'.b
@de ZZ
j6s j2D
//获得文件长度 1<:5b%^c
public long getFileSize() &wQ<sVQ0$
{ Cuylozj$&
int nFileLength = -1; r'ilJ("
try{ "d}']M?-h
URL url = new URL(siteInfoBean.getSSiteURL()); =lv(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ll}_EUF|
httpConnection.setRequestProperty("User-Agent","NetFox"); :E{)yT
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int responseCode=httpConnection.getResponseCode(); ^5Y<evjm
if(responseCode>=400) wmpQF<
{ "IS; o o$g
processErrorCode(responseCode); ,3rsjoKhd
return -2; //-2 represent access is error &$ }6:
} eP (*.
q AVypP?J
8K^#$,.."
String sHeader; C;ab-gh
YdV.+v(30
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for(int i=1;;i++) |Ja5O
{ em7L`,
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); pPxgjX
//Utility.log(in.readLine()); M19O^P>[
sHeader=httpConnection.getHeaderFieldKey(i); 0aq{Y7sYU
if(sHeader!=null) Cw^iA U
{ /.s L[X-G
if(sHeader.equals("Content-Length")) '`tFZfT
{ 5xT, O
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ud"_[JtGM
break; .NWsr*Tel
} `]]m$
} Sj)?!
else _G`Q2hf"5
break; =Crl{Ax
} %#fjtbeB
} aQH]hLvs
catch(IOException e){e.printStackTrace ();} zM8 jjB
catch(Exception e){e.printStackTrace ();} k %{q q v
!C4)P3k
2K3j3|T
Utility.log(nFileLength); nUs=PD3)
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3]iw3M
return nFileLength; ZT"vVX-)G
} o^5UHFxTCB
uih8ZmRt
lhQMR(w^
//保存下载信息（文件指针位置） `4ga~Ch
private void write_nPos() [6\O <-?
{ Li8/GoJW-T
try{ fx:vhEX
output = new DataOutputStream(new FileOutputStream(tmpFile)); b4$g$()
output.writeInt(nStartPos.length); 1A93ol=
for(int i=0;i<nStartPos.length;i++) MF$Dx| Tcj
{ 2./z6jXW_
// output.writeLong(nPos); EWl9rF@I
output.writeLong(fileSplitterFetch.nStartPos); ">B&dNrt
output.writeLong(fileSplitterFetch.nEndPos); |+~P; fG
} O*2{V]Y @
output.close(); +-x+c: IxA
} Lcg1X3$G
catch(IOException e){e.printStackTrace ();} uR=*q a
catch(Exception e){e.printStackTrace ();} N f?\O@
} 2/ )~$0
{y|.y~vW
f% 8n?f3;u
//读取保存的下载信息（文件指针位置） Dd OK&
private void read_nPos() 8\)4waz$
{ 3Zz_wr6
try{ dr8Q>(ZY
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %U<lS.i
int nCount = input.readInt(); 7u1o>a%9
nStartPos = new long[nCount]; hQ)?LPUB
nEndPos = new long[nCount]; g}?39?o4
for(int i=0;i<nStartPos.length;i++) 8eCh5*_$
{ amQiH!}8R
nStartPos = input.readLong(); H>\lE2
nEndPos = input.readLong(); }If,O
} "T8b.ng
input.close(); t&yuo E
} W;X:U.
catch(IOException e){e.printStackTrace ();} [ P*L`F
catch(Exception e){e.printStackTrace ();} ee<'j~{A
} ?<OE|nb&
](+u'8
@Rd`/S@
private void processErrorCode(int nErrorCode) E)'T;%
{ Sw{rNzh%$
System.err.println("Error Code : " + nErrorCode); C:!&g~{cKi
} fX LsLh+~D
B|>eKI
I]#x0?D
//停止文件下载 Qc Xw -
public void siteStop() R{B5{~m>W@
{ U~|)=+%O
bStop = true; :p1_ij]ND
for(int i=0;i<nStartPos.length;i++) Oxi^&f||`
fileSplitterFetch.splitterStop(); *EU1`q*
`y"a>gHC
3!KyO)8
} Ngrj@_J
} S>[&]
//负责部分文件的抓取 W Emh
**FileSplitterFetch.java |>JRJ"CFE
*/ U d+6=Us{
package NetFox; U,<?]h
DI :
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import java.io.*; xM&`>`;^e
import java.net.*; 8P%Jky&(
EBmkKiI;
?;rRR48T9E
public class FileSplitterFetch extends Thread { 9:!V":8q
{FNCC*=
%zjyZ{=
String sURL; //File URL t4zKI~cO
long nStartPos; //File Snippet Start Position }.A \;FDyj
long nEndPos; //File Snippet End Position {o%OG/!1
int nThreadID; //Thread's ID ;A?86o'?
boolean bDownOver = false; //Downing is over ^Y"|2 :
boolean bStop = false; //Stop identical oPxh+|0?
FileAccessI fileAccessI = null; //File Access interface I_`$$-|
6(B[(Af
aO *][;0
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7$kTeKiP
{ +W|VCz
this.sURL = sURL; 7MX5hZF"
this.nStartPos = nStart; :<6gP(
this.nEndPos = nEnd; _nIt4l7
nThreadID = id; kc[<5^b5
fileAccessI = new FileAccessI(sName,nStartPos);//定位 q$B|a5a?
} pQCW6X
_o6Zj1p
ib(4Y%U6~
public void run() 7] >z e
{ P.Qz>c^-C
while(nStartPos < nEndPos && !bStop) )9{!=k
{ D' h%.
za5E{<0
a;G>56iw
try{ 70A* !v
URL url = new URL(sURL); /6'5uP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )4FW~o<i
httpConnection.setRequestProperty("User-Agent","NetFox"); l=>FoJf!*<
String sProperty = "bytes="+nStartPos+"-"; Pu2cU5n
httpConnection.setRequestProperty("RANGE",sProperty); JIMi~mEiN
Utility.log(sProperty); Tu=~iQ
fp$U%uj
2()/l9.O'
InputStream input = httpConnection.getInputStream(); Y-v6M3$
//logResponseHead(httpConnection); ^B'N\[
$btk48a7
P\2x9T
byte[] b = new byte[1024]; N}\3UHtO
int nRead; $*+`;PG-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ?fvK<0S`
{ 810uxw{\
nStartPos += fileAccessI.write(b,0,nRead); Nf9$q| %!
//if(nThreadID == 1) %xwtG:IKEV
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zRA,Yi4;+
} ugQySg>
GOY!()F
T:VFyby\w
Utility.log("Thread " + nThreadID + " is over!"); Y-P?t+l
bDownOver = true; xU;Q~(
//nPos = fileAccessI.write (b,0,nRead); 5J*h7
} A~wVY
catch(Exception e){e.printStackTrace ();} *qw//W
} ByW,YKMy
} =BgQSs/^c
Nk$OTDwP
z?g\w6
//打印回应的头信息 y.WEO>
public void logResponseHead(HttpURLConnection con) BA`K,#Ft7
{ QzD8 jk#
for(int i=1;;i++) 'zx1kq1
{ `;3fnTI:1
String header=con.getHeaderFieldKey(i); ()EiBl(kWk
if(header!=null) b[my5Ol
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ka| 8 _C^z
Utility.log(header+" : "+con.getHeaderField(header)); FrQRHbp3
else hR~~k~84
break; -Z&9pI(3R~
} ^r^) &]
} LVNJlRK
)C#b83
e~Z>C>J
public void splitterStop() cy( WD#^
{ Y~-P9
bStop = true; !WQS.&
} uzaDK
h$a%PaVf
!^(?C@TQ
} S0p[Kt
oz/Nx{bg
q,2 +\i
/* eGlPi|
**FileAccess.java dW"=/UW
*//文件访问(定位，写) bK#SxV
package NetFox; E)z=85;_p
import java.io.*; gOLN7K-)
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4I!g?Moh
public class FileAccessI implements Serializable{ GiS:Nq`$(
DuI>z?bS
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /wT<p
RandomAccessFile oSavedFile; J1g+H2
long nPos; g#b9xTGJ^
r2G38/K
Df5!z\dx
public FileAccessI() throws IOException #bwGDF
{ #$ooV1E
this("",0); gnN"6r1
} rBUWzpE"
z=yE- I{
><i: P*ht
public FileAccessI(String sName,long nPos) throws IOException E_-QGE/1
{ FW)VyVFmk
oSavedFile = new RandomAccessFile(sName,"rw"); OAo;vC:^
this.nPos = nPos; ;DXg
oSavedFile.seek(nPos); e6gLYhf&
} ToX--w4
V_/.]zQA
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public synchronized int write(byte[] b,int nStart,int nLen) Yan}H}Oq
{ 9Yd"Y-
int n = -1; ;b_l/T(
try{ ?Sr7c|a2
oSavedFile.write(b,nStart,nLen); >PK 6CR
n = nLen; u\Y3h:@u
} H*HL:o-[
catch(IOException e) SZ1yy["
{ 6_g:2=6S
e.printStackTrace (); L30$
} $8WWN} OC
\>[k0<
b} FhC"'i
return n; %ty`Oa2
} 7KL@[
mI'&!@WG
-car>hQq
} +t%1FkI\
EhAaaG
3?e~J"WXC5
/* c8LMvL
**SiteInfoBean.java Vw]!Kb7tA
*/ eY[kUMo
package NetFox; d9up! k
QJ+Ml
dngG=
public class SiteInfoBean { #Q'#/\5
*vzEfmN:d
IG&twJR
private String sSiteURL; //Site's URL uHq;z{ 2GI
private String sFilePath; //Saved File's Path 8]D0)
private String sFileName; //Saved File's Name P^AI*tH"m
private int nSplitter; //Count of Splited Downloading File 1gQ_76Yck
#I1q,fm
>t{-_4Yv?
public SiteInfoBean() #>6Jsnv1
{//nSplitter的缺省值为5 X0Wx\xDg[
//default value of nSplitter is 5 +ZOKfX
this("","","",5); =Cd{bj.8
} P$Q,t2$A
+;-ZU
zx5#eMD
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |DYgc$2pN
{ G=]ox*BY
sSiteURL= sURL; 0S96x}]J B
sFilePath = sPath; q%LjOPE V
sFileName = sName; [*M':
this.nSplitter = nSpiltter; BA[ uO3\4
#p ;O3E@
V!l?FOSZ
} 4n"6<cO5q
6-z(34&N
)"Z6Q5k^
public String getSSiteURL() Kq5i8L=u
{ #Vu;R5GZ}
return sSiteURL; 1'N<ITb
} C]Y%dQh+a
%o5'M^U
iI>7I<_
public void setSSiteURL(String value) W1521:
{ IXG@$O?y/
sSiteURL = value; N0%q66]1
} #0PZa$kM(o
n =WH=:&
2Z5_@Y
public String getSFilePath() )|_L?q#w!'
{ a?yU;IKJ
return sFilePath; {1qr6P,"
} 1[J|AkN
F2Y!aR
S'\e"w
public void setSFilePath(String value) Npi)R)
{ =?Ui(?tI
sFilePath = value; Kv2S&P|jXM
} |]9L#
zk"8mTg
iCLH
public String getSFileName() TW|- 0
{ vZW[y5
return sFileName; 8+J>jZ
} plp-[eKcD
J.'%=q(Sb
ANNVE},
public void setSFileName(String value) 9ln=f=
{ )ki Gk}2
sFileName = value; ^`B;SSV
} =H3tkMoi2
#4JLWg
z1]nC]2
public int getNSplitter() ;rF[y7\
{ r<4j;"lQK
return nSplitter; Oet+$ b
} .rITzwgB
1=7ASS9
UhrRB
public void setNSplitter(int nCount) m"'}{3$%
{ CmV &+C$V%
nSplitter = nCount; !\$V?*p7
} W+/_0GgQ3
} _m[DieR
>:4`y"0
SZyORN
/* -U\'Emu4
**Utility.java $dXx@6fP
*/ -jy0Kl/p
package NetFox; Fe4>G8uuwn
ca,W:9#.xn
IRwtM'%0
public class Utility { -- FzRO{D
JSi0-S[Y{
V.z8 ]iG
public Utility() wMj#.Jh
{ 8Y.9%@
9^ZtbmUf
dJ m9''T')
} ~D>pu%F
KX]!yA
//线程睡眠 g&y^r/
public static void sleep(int nSecond) Eh ";irE
{ $xbW*w
try{ k}Q<#
Thread.sleep(nSecond); I8j:{*h
} kaXq.
catch(Exception e) IhBc/.&RL
{ p7@R+F\.};
e.printStackTrace (); ~!5=o{wy
} &e@)yVLL
} 2jC`'8
:>2wVN&\c
//日志 !&>`
public static void log(String sMsg) u\L}B!
{ ^a_a%ws
System.err.println(sMsg); 4k-Ak6s
} 8\!E )M|4
BjsT 9?6W/
qSB&Q0T
public static void log(int sMsg) J (?qk
{ *dw.Ug
System.err.println(sMsg); bY=[ USgps
} C[G+SA1&W
} |Rz.Pt6
DegbjqZ#
/De~K+w7o
/* GaG>0x
**TestMethod.java 8>,w8(Nt
*/ `H6~<9r
package NetFox; 3>-h- cpMX
#$-E5R;x
&.\7='$F
public class TestMethod { >#x[qX
=uH2+9.
{V2"Pym?
public TestMethod() ]FZPgO'G
{ ///xx/weblogic60b2_win.exe y'`/^>.
try{ '2*OrY
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &<]f-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); B(++*#T!^m
SiteFileFetch fileFetch = new SiteFileFetch(bean); P .m@|w&.K
fileFetch.start(); .Mb[j1L^
} ur\6~'l4
catch(Exception e){e.printStackTrace ();} dY S(}U
!T][c~l
`.@sux!lu
} YE{ [f@i0
.{h"0<x
BZ?Ck[E]Z
public static void main(String[] args) |cf-S8pwY
{ ;na%*G`
new TestMethod(); q\?s<l63
} > 0MP[
} $TXxhd 6
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