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)); AY[7yPP
} [9'5+RXw3
for(int i=0;i<nEndPos.length-1;i++) L6r&Y~+/
{ ;Zw!
nEndPos = nStartPos[i+1]; !yojZG MB
} %nFZA)B[
nEndPos[nEndPos.length-1] = nFileLength; gS4K](KH |
} :M1+[FT
} y{!`4CxF
UF,T
^q%~K{'`-
//启动子线程 bxrByu~|1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; q/m}+v]
for(int i=0;i<nStartPos.length;i++) RNl%n}
{ s ~(qO|d
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K*7*`6iU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5\:#-IYJ
nStartPos,nEndPos,i); ,(OA5%A9zK
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~AjbF(Ad
fileSplitterFetch.start(); $`{}4,5M
} G U0zlG] C
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3|P P+<o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); rH8?GR0<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )K8JDP
nEndPos = " + nFileLength); ir \d8.
// fileSplitterFetch[nPos.length-1].start(); djZOx;/
P)(Ly5$*
D;BFl(l
//等待子线程结束 kki]6_/n
//int count = 0; [MFV:Z
//是否结束while循环 P@k ;Lg"
boolean breakWhile = false; .zBSjh_=H
n." j0kc7=
S9U9;>g
while(!bStop) }eEF/o
{ 6&.[:IHw
write_nPos(); OWtN=Gk
Utility.sleep(500); *M"lUw#(f
breakWhile = true; r>$jMo.S"
`9zP{p
TD!QqLW
for(int i=0;i<nStartPos.length;i++) r}"Ty
{ xV}|G
if(!fileSplitterFetch.bDownOver) {3_M&$jN
{ @zsr.d6Q
breakWhile = false; ,i>5\Yl%
break; U~Uxs\0:
} luat1#~J
} FZjtQ{M
if(breakWhile) k}F;e_
break; p1J%=
>'Y]C\
#<yR:3
//count++; P/M*XUG.
//if(count>4) Bi?.G7>
// siteStop(); _4[kg)#+
} ~Z.lvdA_5
.6e5w1r63
8$?a?7,>|
System.err.println("文件下载结束！"); n?kU
} ${6 ;]ye
catch(Exception e){e.printStackTrace ();} He">kJx
} +SUQRDF@i
Yw?%>L
]=@>;yP)
//获得文件长度 0sV;TQt+f
public long getFileSize() XImb"7|
{ xQWZk`6~L
int nFileLength = -1; `4\H'p
try{ zLf^O%zN
URL url = new URL(siteInfoBean.getSSiteURL()); oE-i`;\8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9FcCq*D
httpConnection.setRequestProperty("User-Agent","NetFox"); ,lL0'$k~
%S$P+B?
Nl;rg*@o
int responseCode=httpConnection.getResponseCode(); A4%0
if(responseCode>=400) %ze Sx
{ %z.u % %
processErrorCode(responseCode); JGGss5
return -2; //-2 represent access is error O?8G
} xV<NeU
MttVgNV
eR8h4M~O
String sHeader; k\HRG@ /G
)7c^@I;7
6M612
for(int i=1;;i++) N-_2d*l3
{ z'fGHiX7.0
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); XK(<N<Z@|e
//Utility.log(in.readLine()); olK%TM[Y
sHeader=httpConnection.getHeaderFieldKey(i); .hETqE`E
if(sHeader!=null) b*?="%eE(
{ sNS!/
if(sHeader.equals("Content-Length")) i]9SCO
{ Hr96sN.R
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "}Ya.
break; el+euOV
} 7th&C,c&
} hj0uv6t.c
else a/>={mbKi
break; |}'}TYX0:
} {,P&05iSi
} Z^h'&c#
catch(IOException e){e.printStackTrace ();} '3%!Gi!g
catch(Exception e){e.printStackTrace ();} Vj~R6
I-fs*yzj;8
pX6OhwkTK
Utility.log(nFileLength); auL?Hb
tao3Xr^?
)0qXZgs
return nFileLength; VPtA %1
} *K-,<hJ#L
dIIsO{Zqv
"F)7!e
//保存下载信息（文件指针位置） TxPP{6t
private void write_nPos() (W*yF2r
{ o7]h;Zg5r
try{ $zxCv7
output = new DataOutputStream(new FileOutputStream(tmpFile)); U/0NN>V
output.writeInt(nStartPos.length); "QGP]F
for(int i=0;i<nStartPos.length;i++) |D`Zi>lv
{ y5+-_x,
// output.writeLong(nPos); {9'"!fH
output.writeLong(fileSplitterFetch.nStartPos); `|v0@-'$
output.writeLong(fileSplitterFetch.nEndPos); }IEYH&4!
} b>I -4
output.close(); $~zqt%}
} ) ,*&rd!
catch(IOException e){e.printStackTrace ();} A+;]# 1y(D
catch(Exception e){e.printStackTrace ();} fwXk{P/
} 1c?,= ;>
:q^g+Bu=
+w GE
//读取保存的下载信息（文件指针位置） TtKBok
private void read_nPos() vEn12s(lj
{ qX-Jpi P
try{ So0YvhZ+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f-4<W0%
int nCount = input.readInt(); T5W r;a
nStartPos = new long[nCount]; IxgnZX4N
nEndPos = new long[nCount]; t2tH%%Rs
for(int i=0;i<nStartPos.length;i++) |$7!u DU8
{ -D{~7&
nStartPos = input.readLong(); `^F'af
nEndPos = input.readLong(); >.J68x
} <[l2]"Q
input.close(); CaZEU(i
} C+-~Gmrb(7
catch(IOException e){e.printStackTrace ();} VY~WkSi[<
catch(Exception e){e.printStackTrace ();} 1sn!!
} v_)cp9d]
^>[DG]g
q& 4Z.(
private void processErrorCode(int nErrorCode) *R1x^t+)
{ !>9*$E |
System.err.println("Error Code : " + nErrorCode); *"j_3vAx
} V,|9$A;
9I30ULm
kc/h]B
//停止文件下载 .R biF
public void siteStop() &<.Z4GxS
{ mxGvhkj
bStop = true; lKH"PH7*_w
for(int i=0;i<nStartPos.length;i++) u+th?KO`
fileSplitterFetch.splitterStop(); |WubIj*\{
"0zMx`Dh
D.R5-
} %#ms`"H
} /KlA7MH6
//负责部分文件的抓取 .-c3f1i
**FileSplitterFetch.java ,iiWVA"
*/ +S0A`rL
package NetFox; x1mxM#ql
G}D?+MWY
>D<nfG<s Z
import java.io.*; hiU_r="*ox
import java.net.*; Ldt7?Y(V(
J6NQ5S\
/=[M
public class FileSplitterFetch extends Thread { )bw>)&)b`
7{az %I$h
sy/J+==
String sURL; //File URL YJeZ{Wws
long nStartPos; //File Snippet Start Position nGX~G^mZ
long nEndPos; //File Snippet End Position _Y\@{T;^Zb
int nThreadID; //Thread's ID $@8\9Y {
boolean bDownOver = false; //Downing is over l]3g6c
boolean bStop = false; //Stop identical 3]xnKb|W
FileAccessI fileAccessI = null; //File Access interface ^b>E_u
pPG!{:YT
fBw+Y4nCO7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException A(;J
{ d'Gv\i&e
this.sURL = sURL; z?1GJ8
this.nStartPos = nStart; '{6`n5:e
this.nEndPos = nEnd; Wu.od|t0
nThreadID = id; %z8@;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =p&6A^
} Er{[83
o)S>x0|[
$V`O%Sz
public void run() %,~; w0
{ JR7~|ov
while(nStartPos < nEndPos && !bStop) $.V(_
{ as o8
[.dNX
fp12-Hk ~
try{ >SfC '*1
URL url = new URL(sURL); j] M)i:n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z13"S(5D~
httpConnection.setRequestProperty("User-Agent","NetFox"); s/P\w"/fN
String sProperty = "bytes="+nStartPos+"-"; rYm<U!k
httpConnection.setRequestProperty("RANGE",sProperty); 8 _`Lx_R
Utility.log(sProperty); ?:n{GK
tGM)"u-
Of([z!'Gc
InputStream input = httpConnection.getInputStream(); Ie4*#N_
//logResponseHead(httpConnection); l*%voKZG
\4zvknk<
hn!$?Vo.
byte[] b = new byte[1024]; 5:n&G[Md
int nRead; r\=p.cw<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) y7,~7f!N2
{ o L6[i'H|
nStartPos += fileAccessI.write(b,0,nRead); u$<FKp;I
//if(nThreadID == 1) @@ZcW<Y"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :MJBbrV ,
} tEP^w
Kau*e8
hh:)"<[
Utility.log("Thread " + nThreadID + " is over!"); WxO*{`T!
bDownOver = true; #docBsHX&s
//nPos = fileAccessI.write (b,0,nRead); Dq2eX;c@
} 1Rp|*>
catch(Exception e){e.printStackTrace ();} 7M*+!al9
} YWq[)F@0G
} `4;<\VYCr
jX+LI
BLMcvK\9
//打印回应的头信息 BKvF,f/g
public void logResponseHead(HttpURLConnection con) wJ IJPYTK
{ s/ZOA[Yux
for(int i=1;;i++) %R&3v%$y*
{ ZMx_J
String header=con.getHeaderFieldKey(i); ?{{E/J:%
if(header!=null) /!AdX0dx
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gfr``z=>O
Utility.log(header+" : "+con.getHeaderField(header)); 7zQD.+&L
else HJg)c;u/2;
break; Z$WT ~V
} -t*C-C'"|
} #"7:NR^H^
C: e}}8i
JanLJe)
public void splitterStop() cs@5K$v
{ BAt2m-
bStop = true; VT'$lB%IK
} D4o?
K=06I
Y6{p|F?&"
} jh8%Xu]t
Eda sGCo
ZU "y<
/* % qAhETZ%
**FileAccess.java _f34p:B%s
*//文件访问(定位，写) !+fHdB
package NetFox; eh)J'G]G
import java.io.*; ,&)XhO?
|<BTK_R
xR1g
public class FileAccessI implements Serializable{ r-Dcc;+=Q
5l)p5Bb48c
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ih~c(&n0
RandomAccessFile oSavedFile; -F5U.6~`!
long nPos; ) mv}u~
lbv, jS
x!"!oJG^k
public FileAccessI() throws IOException *FG@Dts^&
{ _BW$?:)9
this("",0); MX9q )(:
} *=;=VUu5
OpH9sBnA
m+uh6IqN./
public FileAccessI(String sName,long nPos) throws IOException F ^E(AE
{ u)Y#&qA
oSavedFile = new RandomAccessFile(sName,"rw"); fylaH(LER
this.nPos = nPos; \t!+]v8f8
oSavedFile.seek(nPos); 3:=XU9p)x
} ?58pkg J
CQtd%'rt6
9sT?"(=
public synchronized int write(byte[] b,int nStart,int nLen) y8<,>
{ SXod r}
int n = -1; +9h6{&yr1
try{ i [j`'.fj
oSavedFile.write(b,nStart,nLen); b#XS.e/uf
n = nLen; XUSfOf(
} <F=j6U7
catch(IOException e) b0KorUr
{ ^k-H$]
e.printStackTrace (); yyA/x,
} 5h20\b?=$
n+!.0d}6
Box,N5AA
return n; CZ&TUE|:DA
} h+$_:](PC
uHf~KYL
Ap97Zcw
} ZFdQZ=.'
|]m&LC
5T8!5EcS*
/* DF&C7+hO
**SiteInfoBean.java 01w=;Q
*/ ;UWdT]>!?
package NetFox; nt5 ~"8
jR/X}XQtY
z%;\q$
public class SiteInfoBean { {{<o1{_H
!P:hf/l[B
qC3 rHT]
private String sSiteURL; //Site's URL -<s?`Rnk
private String sFilePath; //Saved File's Path T`WFY
private String sFileName; //Saved File's Name `*N0 Lbl]
private int nSplitter; //Count of Splited Downloading File m,.d< **
g~V{Ca;}
CMF1<A4]
public SiteInfoBean() PN.=])7T
{//nSplitter的缺省值为5 "3hw]`a}
//default value of nSplitter is 5 %@rh\Z
this("","","",5); @Sv ?Ar
} :'rXu6c-
o oS4F1ta
]gmf%g'C
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?Rl*5GRW
{ wCI.jGSBW
sSiteURL= sURL; i_=P!%,
sFilePath = sPath; 'bT9AV%
sFileName = sName; MA1,;pv6
this.nSplitter = nSpiltter; %{Ls$Y)
>w*"LZjTTK
@D60
} 'wQ=b
3PJ
_5X}&>>lhF
public String getSSiteURL() H$[--_dI{
{ WrD20Q$9Q
return sSiteURL; :V_$?S
} goHr#@
IXg${I}_Q
0[hl&7 Ab@
public void setSSiteURL(String value) S`*al<m
{ 'Lm.`U
sSiteURL = value; mS);bs
} hyTi':
UPgZj\t%{
G A7
public String getSFilePath() ~XZ1,2jA/
{ B\("08x
return sFilePath; +HfjnEbtBs
} aG"UV\
\ _i`=dx
(JM4W "7'
public void setSFilePath(String value) 6dinC <[}
{ Z,d/FC#y(
sFilePath = value; @*c+`5)_
} x[>A'.m@)
8XY4
Q% dpGI
public String getSFileName() (Bmjz*%M
{ )v|a:'%K_
return sFileName; Ne#nSx5,
} #~#_)\l'F
Cw+ (,1
4bJ3uIP#
public void setSFileName(String value) I&cb5j]C
{ (te\!$
sFileName = value; %WO;WxG8^
} =LT({8
F*NIs:3;
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public int getNSplitter() d?S<h`{x
{ 7C 4Njei"
return nSplitter; r[?rwc^
} +0=RC^
*PMql$
`b] NB^/
public void setNSplitter(int nCount) ,)QmQ^/
{ PDir?'
nSplitter = nCount; ;=n7 Z
} 9:kb0oBa?l
} N..u<06j/
2`Pk@,:_
%V+,#
/* Us%VBq
**Utility.java /g8yc'{p
*/ :]//{HF
package NetFox; dIf Jr}ih
t /47lYN)
JN8k x;@
public class Utility { b;}MA7=
t7~mW$}O
AG9U2x
public Utility() BShZ)t
{ Al` ;SWN
G's/Q-'[\
D~%cf
} )q=1<V44d
JRo{z{!O6
//线程睡眠 V,Gt5lL&/!
public static void sleep(int nSecond) pH*L8tT
{ O{dx+f
try{ '@W72ML.
Thread.sleep(nSecond); ,{oANqP
} _{ba
catch(Exception e) |_ @iaLE
{ grS,PKH
e.printStackTrace (); :4Y|%7[
} SMhT>dB
} nBD7
GV2}K <s
//日志 q&N&n%rbm
public static void log(String sMsg) x7*}4>|W,I
{ 3!}#@<j
System.err.println(sMsg); i$F)h<OU+
} $6J5yE
77 `/YE#M
k\%{1oRA
public static void log(int sMsg) dE^'URBiA
{ epwXv|aSZ
System.err.println(sMsg); 8=SNLO
} r>G$u
} hrW.TwK
&3^40s/+
a{8GT2h`4
/* T|}HK]QOX
**TestMethod.java .6tz ^4
*/ /!E /9[V
package NetFox; Uvuvr_IP
S\f^y8*<
"RG.vo7b
public class TestMethod { &{ f5F7E@
FIS-xpv$
*(HH71Y
public TestMethod() c]n4vhUa5
{ ///xx/weblogic60b2_win.exe 8+!$k!=X
try{ ,~3sba
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); u )ld
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); VJNPs6
SiteFileFetch fileFetch = new SiteFileFetch(bean); L,l+1`Jz
fileFetch.start(); ;m&f Vp
} p\,lbrv
catch(Exception e){e.printStackTrace ();} Bq_<v)M*
H`".L^
2.x3^/
} 1'd "O @
)GR^V=o7,Y
m2V4nxw]Qp
public static void main(String[] args) ZNx{7]=a
{ Na`qAj}
new TestMethod(); R<wb8iir
} c"QI`;D_c
} MBg^U<t8
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