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)); Z&;uh_EC
} vZ.x{"n'~
for(int i=0;i<nEndPos.length-1;i++) <HbcNE~
{ ``wSc0\
nEndPos = nStartPos[i+1]; u~A6bK*
} ,l<6GB2\
nEndPos[nEndPos.length-1] = nFileLength; 'Lu__NfN
} '7XIhN9
} z`:lcF{V
(Jz1vEEV
xlQBe-Wg
//启动子线程 4$P0:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; o!)3?
for(int i=0;i<nStartPos.length;i++) On?p 9^9
{ 8-2cRs
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =Xo =Qcr
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :Nz9xD$S5
nStartPos,nEndPos,i); J+`VujWT
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |`.([2
fileSplitterFetch.start(); HDF|{
} l<A|d{"]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #{?qNl8F*J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); zAiXo__x
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !QvZ<5(
nEndPos = " + nFileLength); G K7![p
// fileSplitterFetch[nPos.length-1].start(); ?#fu.YE\
E{|W(z,
R6]Gk)5
//等待子线程结束 6_FE4RR[
//int count = 0; r,h%[JKM
//是否结束while循环 DQr Y*nH
boolean breakWhile = false; RJd(~1
Ymg|4%O@
)c)vTZy
while(!bStop) s,]z[qB#$
{ zx)z/1
write_nPos(); +mn,F};
Utility.sleep(500); , GP?amh
breakWhile = true; HhvdqvIEG
x^y'P<ypw
y!_C/!d
for(int i=0;i<nStartPos.length;i++) -4 SY=NC_
{ @0/+_2MH-
if(!fileSplitterFetch.bDownOver) PK`D8)=u
{ t+!$[K0/
breakWhile = false; JsODzw
break; ^zQ/mo,Z
} `Tv[DIVW
} "$YJX1u3
if(breakWhile) |>dI/_'
break; =w{Z@S(ukz
vkri+:S3
Zcx`SC-0
//count++; e]zBf;9J
//if(count>4) )8$=C#qC[
// siteStop(); ^G}47(
} rR(X9i
% ~H=sjg
u)+8S/ )
System.err.println("文件下载结束！"); E? ;0)'h
} T7hcnF$
catch(Exception e){e.printStackTrace ();} y.< m#Zzt
} %5"9</a&G
\D*KGd]M0
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//获得文件长度 k@k&}N0{
public long getFileSize() rE.;g^4p
{ RwpdRBb
int nFileLength = -1; D$I5z.a
try{ wNpTM8rfU#
URL url = new URL(siteInfoBean.getSSiteURL()); Y,^@P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ).`1+b
httpConnection.setRequestProperty("User-Agent","NetFox"); jK& h~)
5>D>% iaHv
Q7jb'y$ozO
int responseCode=httpConnection.getResponseCode(); h7lDHIQf
if(responseCode>=400) "hH.#5j
{ l~w2B>i)
processErrorCode(responseCode); U@uGNMKR
return -2; //-2 represent access is error w"Gm;B4
} of%Ktm5Qi
@1o/0y"
C26>BU<
String sHeader; 3u*4o=4e
\o*5
)<h*eS{
for(int i=1;;i++) KY$)#i
{ >4TaP*_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); r\'A i6
//Utility.log(in.readLine()); o$jLzE"
sHeader=httpConnection.getHeaderFieldKey(i); uKUiV%p!
if(sHeader!=null) g| I6'K!<
{ O;:mCt _H
if(sHeader.equals("Content-Length")) (MxQ+D\
{ MOQ*]fV:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); d928~y W
break; \`~Ly-
} "n(hfz0y%
} >UiYL}'br6
else ^ *k?pJ5
break; jFL #s&ft
} P}n_IV*@
} ,Z&xNBX
catch(IOException e){e.printStackTrace ();} '"0'Oua
catch(Exception e){e.printStackTrace ();} 1ySk;;3
'YmIKIw
g?goZPZB
Utility.log(nFileLength); f e\$@-
zPn+V7F
"O3tq=Q
return nFileLength; vWzm@
} ` Mjj@[
*\+\5pu0
I_}SB|
//保存下载信息（文件指针位置） CkOz
private void write_nPos() c|e~BQdRw
{ [%y';`( x
try{ [1g8*j~L
output = new DataOutputStream(new FileOutputStream(tmpFile)); zy/@ WFPE
output.writeInt(nStartPos.length); a*lh)l<KV
for(int i=0;i<nStartPos.length;i++) pjKWtY@=X
{ `VA"vwz
// output.writeLong(nPos); =Y{(%sn
output.writeLong(fileSplitterFetch.nStartPos); <\rT%f}3^
output.writeLong(fileSplitterFetch.nEndPos); UZ\u;/}
} 4":KoS`,j
output.close(); _|kxY'_[8
} J=9FRC
catch(IOException e){e.printStackTrace ();} P{kur} T
catch(Exception e){e.printStackTrace ();} /M1ob:m
} j4gF;-m<
N.,X<G.H
`i3NG1 v0
//读取保存的下载信息（文件指针位置） q9KHmhUD
private void read_nPos() fInb[
{ 0L2F[TN
try{ DR5\45v
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 36}?dRw#p
int nCount = input.readInt(); o4G?nvK-
nStartPos = new long[nCount]; CGW.I$u
nEndPos = new long[nCount]; T*Y~\~Jhu
for(int i=0;i<nStartPos.length;i++) [kVS O
{ ?GKb7Oj
nStartPos = input.readLong(); >)fi^
nEndPos = input.readLong(); q/4J.jL
} 9UdM`v)(
input.close(); rK'L6o
} EH+"~-v)ae
catch(IOException e){e.printStackTrace ();} gX@HO|.t
catch(Exception e){e.printStackTrace ();} }eCw6
} H%qsjB^
1gL2ia
!#], hok8X
private void processErrorCode(int nErrorCode) Vz~{UHH6
{ ?8npG]L)
System.err.println("Error Code : " + nErrorCode); tU}h~&M
} @K &GJ
g1/:Q%R,
l%k\JY-
//停止文件下载 jwc)Lj}
public void siteStop() E:UW#S%A f
{ [A+ >^ {
bStop = true; orzZ{87
for(int i=0;i<nStartPos.length;i++) l: HTk4$0
fileSplitterFetch.splitterStop(); p|X"@kuseO
?AK(|
T,,WoPU8t
} Sq>dt[7
} DrKP%BnS
//负责部分文件的抓取 "%`1]Fr
**FileSplitterFetch.java dU&a{$ku[
*/ K[I=6
package NetFox; d~9A+m3b_
zGb|)A~,
F+YZE[h%
import java.io.*; f',Op1o
import java.net.*; \j@OZ
1!xQ=DU"
6dq(T_eG
public class FileSplitterFetch extends Thread { epA:v|S
l5S aT,%
;v}GJ<3
String sURL; //File URL j$M h+5
long nStartPos; //File Snippet Start Position q}i]'7
long nEndPos; //File Snippet End Position -o^7r@6
int nThreadID; //Thread's ID U$O\f18
boolean bDownOver = false; //Downing is over m ifxiV
boolean bStop = false; //Stop identical wT6"U$cV
FileAccessI fileAccessI = null; //File Access interface pj\u9 L_
qzYwt]GNS
R5N%e%[
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException CuaVb1r
{ =6j&4p `
this.sURL = sURL; R{C(K(5/
this.nStartPos = nStart; x>**;#7)
this.nEndPos = nEnd; SL Ws*aq
nThreadID = id; u(z$fG:g
fileAccessI = new FileAccessI(sName,nStartPos);//定位 qk%;on&`
} C8J[Up
{c6=<Kv
`!obGMTQ<
public void run() &p'Y^zL-
{ hr#M-K
while(nStartPos < nEndPos && !bStop) 4`4kfiS$
{ Tm~" IB*
cXA i k-
Eq%}
try{ \{Y 7FC~
URL url = new URL(sURL); &C`Gg<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); E(*0jAvO[z
httpConnection.setRequestProperty("User-Agent","NetFox"); D#_3^Kiawj
String sProperty = "bytes="+nStartPos+"-"; :NhO2L
httpConnection.setRequestProperty("RANGE",sProperty); G!Op~p@Jm
Utility.log(sProperty); cVXLKO
0eT(J7[ <
'j`=if
InputStream input = httpConnection.getInputStream(); 2i)^!c
//logResponseHead(httpConnection); `LrHKb aP
bBiE
P}Gj%4/G
byte[] b = new byte[1024]; M,j U}yD3
int nRead; %:M^4~dc
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ${<%" hR$
{ LD+{o4i
nStartPos += fileAccessI.write(b,0,nRead); 216RiSr*
//if(nThreadID == 1) iW)8j 8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); n4O]8C'lW9
} k9<;woOBO
35h8O,Y
+jAGGv^)
Utility.log("Thread " + nThreadID + " is over!"); fW{(lPx
bDownOver = true; {0L1X6eg
//nPos = fileAccessI.write (b,0,nRead); S(k3 `;K
} ^%d\qd`
catch(Exception e){e.printStackTrace ();} YX!{P=Ua
} zykT*V
} hwPw]Ln/
%41m~Wh2
Mer/G2#&
//打印回应的头信息 ^ sOQi6pL
public void logResponseHead(HttpURLConnection con) &xU[E!2H%
{ `"Jj1O@
for(int i=1;;i++) S-a]j;U
{ `68@+|#
String header=con.getHeaderFieldKey(i); J!AgBF N4
if(header!=null) > $O]Eu!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Z-$[\le
Utility.log(header+" : "+con.getHeaderField(header)); $POu\TO
else )cW#Rwu_A4
break; gt\E`HB8E
} 3$9s\<j
} O\ GEay2
l3{-z4mw
"0V.V>-p
public void splitterStop() ?1*cO:O
{ 8Q.T g.
bStop = true; ])[[ V!1
} OyStqi
;(b9#b.
U#0Q)
} 46}g7skD
.ODU
]MqMQLG0t
/* OsTc5K.U~
**FileAccess.java g1;:KzVv
*//文件访问(定位，写) zv|2:4H
package NetFox; l^! ?@Kg,z
import java.io.*; 5us:adm[pD
X@--m6-
Ja|5 @
public class FileAccessI implements Serializable{ ;"xfOzQ
\Q {m9fE
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _jvxc'6
RandomAccessFile oSavedFile; [xK3F+
long nPos; R#s)r
E7WK (
>Ifr [
public FileAccessI() throws IOException I:E`PZ
{ MH =%-S
this("",0); FDv<\2+ c
} X1:V<,}"
6{@w="VT
k6;?)~.
public FileAccessI(String sName,long nPos) throws IOException aH yx_B
{ 2VPdw@"~}
oSavedFile = new RandomAccessFile(sName,"rw"); J9..P&c\
this.nPos = nPos; ISzqEi
oSavedFile.seek(nPos); $6#CqWhI
} Je';9(ZK
gl~ecc
Z< 1
public synchronized int write(byte[] b,int nStart,int nLen) rbul8(1h
{ !-g{[19\
int n = -1; ]dF ,:8
try{ 9G9t" {
oSavedFile.write(b,nStart,nLen); ?Lx24*5%
n = nLen; .zr-:L5{
} $6qh| >z.
catch(IOException e) gLb`pCo/
{ imVo<Je7z(
e.printStackTrace (); UI0(=>L
} ;RH;OE,A
2my_;!6T[
8mCxn@yV
return n; EHSlK5bD,
} OP;v bZ
#F:p-nOq
2kqup)82e
} q'+)t7!
7( #:GD
T*I{WW
/* \Yy$MLs
**SiteInfoBean.java ['b}QW@Fx
*/ Z/G ev"p
package NetFox; w3N[9w?1
0}<|7?
3t.l5m Rg5
public class SiteInfoBean { Z3%}ajPu[
#^#PPO
[m->5H
private String sSiteURL; //Site's URL 36.Z0Z1'F>
private String sFilePath; //Saved File's Path ke!?BZx
private String sFileName; //Saved File's Name 'Oxy$U
private int nSplitter; //Count of Splited Downloading File XUrXnz|>
PG2:~$L0
(|F*vP'
public SiteInfoBean() )tG\vk=@
{//nSplitter的缺省值为5 sZ'nYo
//default value of nSplitter is 5 H!c@klD
this("","","",5); 9U7nKJ+iby
} ,t3wp#E2#
G%BjhpL
2L!u1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) V#v`(j%
{ b}\N;D.{
sSiteURL= sURL; evenq$ H
sFilePath = sPath; +20G>y=+
sFileName = sName; RXNn[A4xfY
this.nSplitter = nSpiltter; fAF1"4f
S2E8Gq9
GeI-\F7b
} Cwr~HY
^0Zf,40
N1}c9}
public String getSSiteURL() I) rCd/
{ O3;u G.:1
return sSiteURL; ky8_UnaO
} ht|z<XJ
T=<@]$?
'-QwssE
public void setSSiteURL(String value) oL-]3TY~
{ q$p%ZefZ
sSiteURL = value; ) g0%{dfJ
} U] ~$g}!)
$': E\*ICb
C,wL0Yj[
public String getSFilePath() }q`ts=dlGt
{ +00b)TF
return sFilePath; UMv.{iEj
} dA#Q}.*r
DP[IZC
s:?SF.
public void setSFilePath(String value) ksc;X$f&4
{ 2iHUZzz\
sFilePath = value; !NIhx109q
} @X%C>iYa9
]Gzm^6v
D!@Ciw
public String getSFileName() Yf:IKY
{ -^K"ZP1
return sFileName; Amp#GR1CA
} y?rPlA_
\j+1V1t9
iMAfJ-oN
public void setSFileName(String value) )5rb&M}
{ 6uv#de
sFileName = value; bNm#tmSt
} ICpAt~3[M
jGJLSEe_
.I$qCb|FP
public int getNSplitter() kd>hhiz|
{ j1^I+j)
return nSplitter; 1!ii;s^e
} R"4Vtww
1=r#d-\tR
4Fa~Aog
public void setNSplitter(int nCount) "C}b%aO:
{ v;BV@E0}x
nSplitter = nCount; Ld\R:{M"
} aL*&r~`&e'
} Mh~q//
Olt`:;j-
) dn(G@5
/* T m,b,hi$
**Utility.java 2-&k^Gl!:
*/ nx@=>E+a
package NetFox; g~ZvA(`
56}U8X
NYyh|X:m
public class Utility { gRrL[z
|^0XYBxQ
H]P. x!I
public Utility() J cPtwa;q@
{ *,3SGcYdJj
D~biKrg?=
;>#wU'
} < nXL
ht7l- AK
//线程睡眠 00'%EYO
public static void sleep(int nSecond) :X0k]p
{ ]@dZ{H|
try{ }]e-{C}
Thread.sleep(nSecond); ?Fi=P#
} ]|!OP
catch(Exception e) F{Z~ R
{ #eQJEajv5
e.printStackTrace (); rEv@YD
} 2gc/3*F8
} gaQdG=G8$
#J@[Wd
//日志 s2teym,uG
public static void log(String sMsg) 0x'#_G65y
{ ZNJ@F<
System.err.println(sMsg); %+f>2U4I
} >,TUZ
zer%W%
vBRQp&YwX
public static void log(int sMsg) J3,fk)
{ !i{aMxUP
System.err.println(sMsg); Z LB4m`
} 0Z~p%C<LW
} Z?}dq-Vh&
'w!Cn>
8?J&`e/
/* ZU85P0
**TestMethod.java V}bjK8$$
*/ 4\y/'`xm)6
package NetFox; 2w59^"<,
mlixIW2
?a8^1:
public class TestMethod { }0eF~>Df
y6LWx:
lH-/L(h2
public TestMethod() Z9:-rcr
{ ///xx/weblogic60b2_win.exe M|6A0m#Q
try{ [.m`+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Yb+yw_5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \wo?47+=
SiteFileFetch fileFetch = new SiteFileFetch(bean); >[MX:Yh
fileFetch.start(); `)` n(B
} 0C1pt5K
catch(Exception e){e.printStackTrace ();} "|Xk2U
Gnf~u[T6
O?)3VT*
} *194{ ep
jNTjSX
YwteZSbp6M
public static void main(String[] args) iEd\6EZ
{ 1HXjN~XF
new TestMethod(); DAS/43\
} J]v%q,"
} aIJt0;
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