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)); NsPAWI|4
} f:\)oIW9Kk
for(int i=0;i<nEndPos.length-1;i++) <:n!qQS6
{ azs lNL
nEndPos = nStartPos[i+1]; ?Z0NHy;5
} rN3qTp
nEndPos[nEndPos.length-1] = nFileLength; ~E8L,h~
} [$Dzf<0
} 8t)?$j$
F3?PlH:Y
Q)IL]S
//启动子线程 nxjP4d>
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; X([8TR
for(int i=0;i<nStartPos.length;i++) /<R[X>]<F
{ @W1F4HYds
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +W%3VV$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), > u!# 4
nStartPos,nEndPos,i); vG{lxPIj
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nOCCOTf
fileSplitterFetch.start(); .eHOG]H
} ]aMeMhe-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W>o>Y$H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;:]#Isq
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", jU9\BYUg
nEndPos = " + nFileLength); u)4eu,MBT
// fileSplitterFetch[nPos.length-1].start(); S8dX8,qg
W^k|*Y|
c+:XaDS-
//等待子线程结束 T&q0TBT
//int count = 0; '@{Mq%`
//是否结束while循环 V{{Xz:
boolean breakWhile = false; YAsE,M+
$`&zIz
?/1Eu47
while(!bStop) $X_A74(
{ 8W2oGL6
write_nPos(); =L]GQ=d
Utility.sleep(500); BW x=Q
breakWhile = true; [e`e bn[C
:V!F~
M-V{(
for(int i=0;i<nStartPos.length;i++) (Zoopkxw
{ I/hq8v~S
if(!fileSplitterFetch.bDownOver) I /z`)
{ l2ARM3"
breakWhile = false; v+vM:At4
break; AF\gB2^
} va[r~
} ZZ324UuATX
if(breakWhile) EdTR]}8
break; ae>B0#=
T9\G,;VQ7/
e|d~&Bk0
//count++; =$-+~
//if(count>4) JFu9_=%+
// siteStop(); 8P*d
} 1d 1 ~`B
se@?:n1)
w2) @o>w
System.err.println("文件下载结束！"); dT7!+)s5-
} >zo_}A!
catch(Exception e){e.printStackTrace ();} /liZ|K3A
} g`(3r
)?{jD
a];1)zVA6
//获得文件长度 2&zklXuo:
public long getFileSize() )lH`a
{ ?UV|m
int nFileLength = -1; JqV}>"WMV
try{ dK41NLGQ
URL url = new URL(siteInfoBean.getSSiteURL()); 7hhv/9L1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z#B(1uI
httpConnection.setRequestProperty("User-Agent","NetFox"); )I"I[jDw
:n,x?bM
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int responseCode=httpConnection.getResponseCode(); [nf5<
if(responseCode>=400) @~bP|a
{ g&rz*)|/
processErrorCode(responseCode); gu"@*,hL
return -2; //-2 represent access is error eig{~3
} U%n>(!d
e F)my
9t!Agxm
String sHeader; V8rS~'{\
LKBh{X0%(
tYp 185
for(int i=1;;i++) biPj(Dd
{ *).!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7c!#e=W@B
//Utility.log(in.readLine()); S3s6
sHeader=httpConnection.getHeaderFieldKey(i); tL M@o|:
if(sHeader!=null) $Lz!04
{ 2U3e!V
if(sHeader.equals("Content-Length")) LIll@2[
{ HWFLu
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &crR nv?
break; n~ZZX={a
} (Q=:ln;kM
} 1DlXsup&?#
else &3Lhb}m
break; zt!7aVm n
} \Vpv78QF;
} ^kke
catch(IOException e){e.printStackTrace ();} PZVH=dagq
catch(Exception e){e.printStackTrace ();} BIEq(/-
_WZ{i,
tRo` @eEX
Utility.log(nFileLength); ]Upr<!
)q`.tsR>
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return nFileLength; ~14|y|\/
} xd\ml 37~
2f1Q&S
+BDW1%
//保存下载信息（文件指针位置） ;ik,6_/Y
private void write_nPos() WcY$=\7
{ z4(`>z2a
try{ S$gLL kD1
output = new DataOutputStream(new FileOutputStream(tmpFile)); luW"|
output.writeInt(nStartPos.length); I>q!co9n
for(int i=0;i<nStartPos.length;i++) .<Ays?
{ m6'9Id-:L
// output.writeLong(nPos); x.$cP
output.writeLong(fileSplitterFetch.nStartPos); hhz#IA6,
output.writeLong(fileSplitterFetch.nEndPos); uzT+,
} o_BRsJy
output.close(); ;GKL[tI"
} my/KsB
catch(IOException e){e.printStackTrace ();} abv*X1
catch(Exception e){e.printStackTrace ();} 9m)gp19YA
} *U}-Y*
e.^?hwl
)!U@:x\K
//读取保存的下载信息（文件指针位置） fg lN_
private void read_nPos() DWEDL[{
{ |UB)q5I
try{ p+5J
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); T]/5aA4
int nCount = input.readInt(); fP6\Ur
nStartPos = new long[nCount]; YWJ$Pp
nEndPos = new long[nCount]; _s<s14+od
for(int i=0;i<nStartPos.length;i++) ^IyYck'y+
{ y^[t3XA6Q
nStartPos = input.readLong(); A@Lr(L
nEndPos = input.readLong(); uF1&m5^W
} sSc~q+xz
input.close(); P#Whh
} T1R~^x1
catch(IOException e){e.printStackTrace ();} j9yOkaVEg
catch(Exception e){e.printStackTrace ();} ng~LCffpY
} .C&kWM&j
d`C$vj
X|/RV4x@Cq
private void processErrorCode(int nErrorCode) gK(G1
{ }p-/R'
System.err.println("Error Code : " + nErrorCode); `.dwG3R
} rqnxRq
+0j{$MPZ
j8 `7)^
//停止文件下载 _n!>*A!
public void siteStop() )v*k\:Hw
{ $06('Hg&
bStop = true; US=K}B=g
for(int i=0;i<nStartPos.length;i++) OCJt5#e~A
fileSplitterFetch.splitterStop(); ?m+];SJk
O*bzp-6\
R'6(eA[K
} (:o:_U
} >8x)\'w
//负责部分文件的抓取 /R?[/`)f&
**FileSplitterFetch.java %#PWD7a\
*/ P-$ ,
package NetFox; = Ezg3$%-
U;*t5l
lrwQ >N
import java.io.*; <Rs$d0/
import java.net.*; S:Jg#1rww-
){z#Y#]dP
Iz83T9I&
public class FileSplitterFetch extends Thread { MxUbx+_N
l_$>$d
ixK9/5T
String sURL; //File URL Mk=*2=d
long nStartPos; //File Snippet Start Position 'Z=_zG/RX
long nEndPos; //File Snippet End Position H=*0KX{
int nThreadID; //Thread's ID 5''k|B>
boolean bDownOver = false; //Downing is over `HnZ{PKf
boolean bStop = false; //Stop identical ]Hq,Pr_+
FileAccessI fileAccessI = null; //File Access interface @o*~\E<T
jcvq:i{
+'iqGg-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4}t&yu<P>
{ K7.ayM 0
this.sURL = sURL; =R 4]Kf
this.nStartPos = nStart; kOdpW
this.nEndPos = nEnd; OwPHp&{ Y
nThreadID = id; auX(d -m
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _Ve)M%
} b<#zgf
b/JjA
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public void run() i%F2^R@!q/
{ :is2 &-|x
while(nStartPos < nEndPos && !bStop) EE|c@M^
{ zBwqIJfM
<HTz
K>LS8,8V
try{ R]Z#VnL@qz
URL url = new URL(sURL); nT2b"wkTT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Nu3IYS5&
httpConnection.setRequestProperty("User-Agent","NetFox"); ]bmf}&
String sProperty = "bytes="+nStartPos+"-"; d0|{/4IWw;
httpConnection.setRequestProperty("RANGE",sProperty); 0-aaLC~Z>
Utility.log(sProperty); 0S4Y3bac&
Z%LS{o~LK.
u rQvJ
InputStream input = httpConnection.getInputStream(); E BoC,{R#
//logResponseHead(httpConnection); jk_yrbLc
d8R|0RZ
uPN^o.,/.
byte[] b = new byte[1024]; uHbbPtk
int nRead; e]ST0J"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1M?x,N_W
{ ]]`[tVaFr
nStartPos += fileAccessI.write(b,0,nRead); 1:M'|uc
//if(nThreadID == 1) 23K#9!3
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >gq=W5vN(
} |0>rojMq
$sb@*K}:4
$7xfLS8Vo
Utility.log("Thread " + nThreadID + " is over!"); dD'KP4Io@
bDownOver = true; <;>k[P'
//nPos = fileAccessI.write (b,0,nRead); D'{o3Q,%K
} sAs`O@
catch(Exception e){e.printStackTrace ();} EV* |\ te
} mr_NArF
} X|g5tnsj`
J8@+)hn
|a /cw"
//打印回应的头信息 j5[>HL
public void logResponseHead(HttpURLConnection con) f*hnzj
{ : 4lR`%
for(int i=1;;i++) N!v>2"x8q
{ 'u%_Ab_H
String header=con.getHeaderFieldKey(i); yDe*-N\'W
if(header!=null) :x3DuQP
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 6 !fq658
Utility.log(header+" : "+con.getHeaderField(header)); &Q\k`0vzVB
else ZD$I-33W
break; zH~g5xgh
} " ;8kKR
} fHI@' '0
Sn.I{~
u8<Fk !
public void splitterStop() @Y(7n/*
{ v] Xy^7?
bStop = true; g&ba]?[A
} )^)|b5,
u+jx3aP:
eB,@oo%
} jlUT9Zp
\tS| N40
H66~!J0;a
/* ms+gq
**FileAccess.java 0d`lugf
*//文件访问(定位，写) *s2 C+@ef
package NetFox; ,p..h+l
import java.io.*; :O;uP_r9
d+8|aS<A
L>57eF)7
public class FileAccessI implements Serializable{ 5y~B/.YY
)$2h:dw_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9!D c=
RandomAccessFile oSavedFile; 2qKAO/_O
long nPos; 8{CBWXo$)
_9iF`Q
cavzXz
public FileAccessI() throws IOException ~@D!E/hZx
{ /"1[qT\F
this("",0); "+4r4
} w/CD-
g8Zf("
7{=+Va5
public FileAccessI(String sName,long nPos) throws IOException *AYjMCo
{ }iB>3|\
oSavedFile = new RandomAccessFile(sName,"rw"); M;@/697G
this.nPos = nPos; P?iQ{x}w~
oSavedFile.seek(nPos); 0LUw
} "LVN:|!
v%Su#xq/
byj7c(
public synchronized int write(byte[] b,int nStart,int nLen) o7:"Sl2AD
{ V%J_iY/BUb
int n = -1; t~]tw
try{ %TQ5#{Y
oSavedFile.write(b,nStart,nLen); yrrP#F
n = nLen; [\ppKC
} J)=Ts({
catch(IOException e) Be0v&Q_NK
{ t-J\j"~%+
e.printStackTrace (); th|TwD&mO
} ZL- ` 3x
xgB-m[Xi
&uu69)u
return n; j|(bdTZY:
} #K[6Ai=We}
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0]t7(P"F6
} ~^"s.Lsb
k|_LF[*Z
n'Z5rXg
/* I~U;M+n*y
**SiteInfoBean.java [c#?@S_
*/ EcmyY,w
package NetFox; QU^?a~r
Q!}LtR$
H-Or
public class SiteInfoBean { )u_[cEJHO
BYsQu.N
W q>qso
private String sSiteURL; //Site's URL Gw}b8N6E
private String sFilePath; //Saved File's Path ST^{?Q
private String sFileName; //Saved File's Name $3 ~/H"K
private int nSplitter; //Count of Splited Downloading File l( 0:CM
}Fgp*x-G
yM*<BV
public SiteInfoBean() *v9 {f?
{//nSplitter的缺省值为5 nL-kBW Ed>
//default value of nSplitter is 5 7e`h,e=
this("","","",5); 3r,^is
} sBm/9vu
)qV&sru.$
TP&&' 4?D1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) d7Devs k
{ >>HC|
sSiteURL= sURL; ,*'aH z
sFilePath = sPath; 2*@.hBi
sFileName = sName; ?;)F_aHp
this.nSplitter = nSpiltter; lC(g&(\{
b&Go'C{p
"?TKz:9r
} piKR*|F
WL/9r *jW
0}y-DCuQ
public String getSSiteURL() nvnJVkL9s
{ Qp]-4%^Vz
return sSiteURL; _q dLA
} :*{\oqFn~$
`di/nv)
y153ax
public void setSSiteURL(String value) JqYt^,,Q:
{ [E/}-m6g
sSiteURL = value; hz_F^gF
} 1|zy6
8cyC\Rs
|;6l1]hk6
public String getSFilePath() qo"_w%{
{ SR\F2@u
return sFilePath; @n:.D9
} v<U +&D{
'+{dr\nJ
GBsM?A:
public void setSFilePath(String value) \9t6#8
{ %/x%hs;d
sFilePath = value; wk"zpI7L
} Z6vm!#\
lm;G8IP`
P?P))UB5
public String getSFileName() h*GU7<F:a
{ SMdkD]{g
return sFileName; XUyoZl?
} =wy3h0k^
Z*rA~`@K6
I^z$0
public void setSFileName(String value) NJglONO
{ 1"82JN|!
sFileName = value; axW4cS ?
} cOr@dUSL
S(f V ,;Z
?)~j>1"S
public int getNSplitter() 8/y~3~A{D
{ D< 4!7*9%
return nSplitter; 'Na/AcRdg
} 5vso%}c
j>0~"A
r2*'5jk_
public void setNSplitter(int nCount) ^{W#ut>IN
{ >5jHgs#
nSplitter = nCount; h8yv:}XU*
} y=jTS
} DgLSDKO!
drQioH-
DjT ekn
/* {mp;^/O`er
**Utility.java 'd"\h#
*/ QJG]z'c+
package NetFox; zq5_&AeW
diLjUC`69
Wsr #YNhx|
public class Utility { R<!WW9IM
N!fp;jvG
`f:5w^A
public Utility() A*h)p@3t<
{ 3\,TI`^C
Z6b3gV
)W@H
} tc{23Rf%
Hc@Z7eQ3^
//线程睡眠 uREc9z`Q'
public static void sleep(int nSecond) #oYX0wvl
{ Oz9k.[j(
try{ >NE]TZ.F
Thread.sleep(nSecond); 55oLj.l^j
} q\[31$i$
catch(Exception e) ,gU9ywg
{ <MN+2^ed&
e.printStackTrace (); XEZ6%Q_
} 7l Aa6"Y68
} gzDb~UEoF
"VWxHRVg4M
//日志 {\t:{.F A
public static void log(String sMsg) JoZC+G
{ Smk]G))o{
System.err.println(sMsg); LM _4.J
} !*%3um
,)L.^<
[uRsB5
public static void log(int sMsg) >[xQUf,p
{ PJAir8
System.err.println(sMsg); c_^H;~^rL
} @V:b Co
} o7 !@WOeZ3
dm$:xE":
72-@!Z0e
/* Fr%KO)s2
**TestMethod.java I)B2Z(<Q
*/ *pasI.2s#
package NetFox; A)7'\JK7b
QW2% Gv:
TU. h
public class TestMethod { C1G Wi4)
FpRK^MEkG
m dC. FO-
public TestMethod() NM]6 o
{ ///xx/weblogic60b2_win.exe d&'6l"${
try{ *gT TI;:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); F37,u|
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); U3U eTa_
SiteFileFetch fileFetch = new SiteFileFetch(bean); ac&tpvij
fileFetch.start(); HRw,D=
} E_yh9lk
catch(Exception e){e.printStackTrace ();} YT:5J%"
ng 6G<hi
i([A8C_A
} fg1 zT~
|n&6z
)US)-\^
public static void main(String[] args) a,tP.Xsl
{ (Pu*[STTT
new TestMethod(); ):[[Ch_
} n+i}>3'A
} 54)}^ftY^
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