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)); q(C<w
} ]g0h7q)79
for(int i=0;i<nEndPos.length-1;i++) c@xQ2&i
{ g AZe&"K
nEndPos = nStartPos[i+1]; j4fv-{=$
} Dno'-{-
nEndPos[nEndPos.length-1] = nFileLength; Z<2j#rd
} 3{j&J-
} )^^Eh=Kbj
$afE= qC*
&0='z
//启动子线程 &LD=Zp%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9BA*e-[
for(int i=0;i<nStartPos.length;i++) [IgB78_$
{ ^ rB7&96C,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2[;4D/`*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), GqT0SP
nStartPos,nEndPos,i); jLy3c@Dp
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y>l92=G
fileSplitterFetch.start(); z|5Sy.H>
} s?g`ufF.t
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {@7{!I|eD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); M~uX!bDH
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?;dfA/
nEndPos = " + nFileLength); AzmISm
// fileSplitterFetch[nPos.length-1].start(); 9:\YEs"
PU\?eA
:qQpBr$
//等待子线程结束 G+$A|'<`z
//int count = 0; 13X\PO'9
//是否结束while循环 l^$8;$Rq
boolean breakWhile = false; PI5a'k0F
Y4 <
XC D&Im
while(!bStop) -hpJL\ng
{ P`$"B0B)
write_nPos(); yL#bZ9W }
Utility.sleep(500); JTw3uM, e
breakWhile = true; ~$PQ8[=
s:fy *6=[Z
MBO3y&\S4
for(int i=0;i<nStartPos.length;i++) '0juZ~>}
{ TO|&}sDh
if(!fileSplitterFetch.bDownOver) LG/6_t}
{ e_6-+l!f
breakWhile = false; e9 `n@
break; Uo7V)I;o
} h ?Ni5
} IQ`#M~:
if(breakWhile) ^-24S#KE
break; QS*!3?%
O6[,K1,
xMb)4cw}
//count++; 64hl0'67y
//if(count>4) DAPbFY9
// siteStop(); %e71BZo~^s
} YjT7_|`(]
j?YZOO>X
k$u/6lw]IB
System.err.println("文件下载结束！"); sUki|lP
} "/O`#Do/
catch(Exception e){e.printStackTrace ();} \"X<\3z2
} Tr} r` %
[ ;$(;
20O\@}2q2M
//获得文件长度 'rX!E,59
public long getFileSize() ~`<(T)rs
{ 6;:s N8M+1
int nFileLength = -1; xjplJ'jB
try{ **%/Ke[
URL url = new URL(siteInfoBean.getSSiteURL()); k6pXc<]8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vwlPFrLl
httpConnection.setRequestProperty("User-Agent","NetFox"); dCF!.
!5/jDvh
}aPx28:/
int responseCode=httpConnection.getResponseCode(); FBR]) h'Z
if(responseCode>=400) 7LQLeQvB
{ Fk(+S:{yQ
processErrorCode(responseCode); &6yh4-(7
return -2; //-2 represent access is error ~; emUU
} \G!TC{6
"'@iDq%y
cr&sI=i
String sHeader; SXA`o<Ma
AaVj^iy/X
$Ka-ZPy<#
for(int i=1;;i++) 7AE)P[
{ ~ PO)>;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <Ag`pZ<s
//Utility.log(in.readLine()); c']3N
sHeader=httpConnection.getHeaderFieldKey(i); z^KMYvH g
if(sHeader!=null) zB8 @Wl
{ " ^t3VjN
if(sHeader.equals("Content-Length")) aBH!K
{ &at^~o
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }i"\?M
break; S#kA$yO
} '`/Qr~]
} :#?Z)oQpT
else `<0{U]m
break; M[C9P.O%w
} E%?X-$a
} .5i\L OTd
catch(IOException e){e.printStackTrace ();} J<<Ph
catch(Exception e){e.printStackTrace ();} XtJ_po
\fHtk _
* mzJ)4A
Utility.log(nFileLength); v(=?ge YLo
KqM!7
[SFX;v!9
return nFileLength; 9L$bJO-3
} 8f""@TTp
JDQ7
7_HJ|QB
//保存下载信息（文件指针位置） Y5 BWg
private void write_nPos() gJkk0wokC
{ W'>"E/Tx#O
try{ LSR{N|h+)
output = new DataOutputStream(new FileOutputStream(tmpFile)); +/bT4TkML
output.writeInt(nStartPos.length); yX%Xjo__*t
for(int i=0;i<nStartPos.length;i++) sS 5aJ}Qs
{ l"I G;qO.
// output.writeLong(nPos); yXuF<+CJ
output.writeLong(fileSplitterFetch.nStartPos); zNF.nS}:
output.writeLong(fileSplitterFetch.nEndPos); ;^Q- 1
} %Km^_JM
output.close(); oVG/[e|c'
} O?6ph4'
catch(IOException e){e.printStackTrace ();} 8"fZ>XQ
catch(Exception e){e.printStackTrace ();} tp6-j`7u
} Zj(2$9IU
|;G9K`8
rF/k$_bFt
//读取保存的下载信息（文件指针位置） M<4tjVQ6
private void read_nPos() $jpAnZR- /
{ (}]ae*
try{ :y>$N(.8f
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); z1-JoZ
int nCount = input.readInt(); TqvgCk-
nStartPos = new long[nCount]; [>rX/a%c
nEndPos = new long[nCount]; x&ngCB@O
for(int i=0;i<nStartPos.length;i++) pj~Ao+
{ kw%vO6"q(
nStartPos = input.readLong(); aBBTcN%'
nEndPos = input.readLong(); }mZsK>
} F5hOKUjv
input.close(); Pjs L{,
} bJ~@ k,'
catch(IOException e){e.printStackTrace ();} gc ce]QS
catch(Exception e){e.printStackTrace ();} _iJ8*v8A
} lg9`Z>?
9S.J%*F7
5IwQ<V
private void processErrorCode(int nErrorCode) WOv m%sX
{ {^Y0kvnd
System.err.println("Error Code : " + nErrorCode); *!~jHy8F
} $KmhG1*s
#RJFJb/
4axc05
//停止文件下载 ceW,A`J
public void siteStop() U_X/
{ w7(jSPB
bStop = true; 1x"S^j
for(int i=0;i<nStartPos.length;i++) lY.{v]i }
fileSplitterFetch.splitterStop(); (jV_L1D
"@!B"'xg
LW"p/`#<
} Id<3'ky<N
} )kBN]>&R
//负责部分文件的抓取 i^i^g5l!
**FileSplitterFetch.java \-Oq/g{j
*/ /3(|P
package NetFox; A6D@#(D
f vAF0 a
-0 e&>H%
import java.io.*; 3I" <\M4x
import java.net.*; l2AAEB_C.
Y$@?Y/rhR
z_A:MoYfo
public class FileSplitterFetch extends Thread { +2ZBj6 e9
7QOQG:-
fsA-}Qc
String sURL; //File URL f|U J%}$v;
long nStartPos; //File Snippet Start Position @CxXkR
long nEndPos; //File Snippet End Position e5"?ol0
int nThreadID; //Thread's ID ^Hdru]A$2
boolean bDownOver = false; //Downing is over &fIx2ZM[
boolean bStop = false; //Stop identical Ah_Ttj
FileAccessI fileAccessI = null; //File Access interface -C>q,mDJZ
)\!-n]+A
na%DF@Rt#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException y[pU8QSt
{ 8,5H^Bi
this.sURL = sURL; ~ sC<V
this.nStartPos = nStart; qv+8wJ((
this.nEndPos = nEnd; Q#,j,h
nThreadID = id; "#3p=}]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Tej&1'G
} 4!I;U>b b
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k~YZT 8
public void run() k=7+JI"J
{ ZeL v!
while(nStartPos < nEndPos && !bStop) h=1cD\^|qw
{ NIzxSGk|
o:.6{+|N
7[b]%i
try{ -UhSy>m
URL url = new URL(sURL); AXQG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %+1;iuDL
httpConnection.setRequestProperty("User-Agent","NetFox"); _w'N&#
String sProperty = "bytes="+nStartPos+"-"; b6LwKUl
httpConnection.setRequestProperty("RANGE",sProperty); jOE~?{8m
Utility.log(sProperty); `X=2Ff
5@:c6(5$
{eQ')f
InputStream input = httpConnection.getInputStream(); pYtvenBy
//logResponseHead(httpConnection); AzfYw'^&9
/IkSgKJiz\
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byte[] b = new byte[1024]; d{gj8
int nRead; ~<)CI0=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >_<J=8|E
{ iJr 1w&GL$
nStartPos += fileAccessI.write(b,0,nRead); GOzV#
//if(nThreadID == 1) \0^ZNa?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f:).wi Ld
} v4YY6?4
<21@jdu3n,
y{`aM(&
Utility.log("Thread " + nThreadID + " is over!"); Wl4T}j
bDownOver = true; IhRYV`:
//nPos = fileAccessI.write (b,0,nRead); -%h0`hOG{
} [xrM){ItW
catch(Exception e){e.printStackTrace ();} 1\~-No
} E2 5:eEXa
} gLH#UwfJ
M<sY_<z
.2si[:_(p
//打印回应的头信息 =Y0>b4
public void logResponseHead(HttpURLConnection con) .ZB/!WiF
{ (t{m(;/
for(int i=1;;i++) )Q!3p={S*
{ */kX|Sur
String header=con.getHeaderFieldKey(i); 7Lv5@
if(header!=null) Wb|xEwqd`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); p{sbf;-x}
Utility.log(header+" : "+con.getHeaderField(header)); W$l%= /
else x;G~c5
break; gA&+<SK(
} xD(RjL+
} Qxvj`Ge
] VN4;R
LvtZZX6!
public void splitterStop() nmc5c/C|-I
{ pO;BX5(x
bStop = true; L&i_
} t]j4PNzn
XHN`f#(w
w(y#{!%+
} Ke_&dgsq
|<YoH$.
X~H~k1
/* 77:s=)
**FileAccess.java TC2gl[
*//文件访问(定位，写) $oJ)W@>
package NetFox; [CfA\-gx<f
import java.io.*; R m{\ R
,sM>{NK9R
iTt#%Fs)4M
public class FileAccessI implements Serializable{ e^Ds|}{V
rRfPq
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !*U#,qY
RandomAccessFile oSavedFile; >-~2:d\M3
long nPos; 0B4&!J
`$X|VAS2
8@S5P$b};
public FileAccessI() throws IOException xSQ0]vE
{ ddR_+B*H
this("",0); w84 ]s%y
} Mohy;#8Wk
Cw=wU/)
dXe. 5XC
public FileAccessI(String sName,long nPos) throws IOException ,r,~1oV<"
{ 7jb{E+DrG
oSavedFile = new RandomAccessFile(sName,"rw"); &I[ITp6y0
this.nPos = nPos; I3 %P_oW'
oSavedFile.seek(nPos); owA0I'|V-A
} 8Jz/'
a-`OE"
.45XS>=z#
public synchronized int write(byte[] b,int nStart,int nLen) %PsDS
{ QSn%~o05
int n = -1; O$><E8q
try{ NjTVinz
oSavedFile.write(b,nStart,nLen); sH^?v0^a
n = nLen; h-XMr_F
} wGqQR)a
catch(IOException e) A0NNB%4|/
{ 4LCgQS6
e.printStackTrace (); 4b"%171
} [N|/d#
I82?sQ7
"4{_amgm&<
return n; A~vZ}?*M
} LE15y>
xLE+"6;W
U`j[Ni}"
} CIM9~:\
8e'0AI_>
!lSxBr[dQ
/* XsldbN^6
**SiteInfoBean.java ~IHjj1s
*/ ^J8sR4p#
package NetFox; nP9@yI*7
~YIGOL"?
>`jsUeS
public class SiteInfoBean { 3^LSK7.:
I5"ew=x#
|~! R5|Q
private String sSiteURL; //Site's URL CS 7"mE`{
private String sFilePath; //Saved File's Path u}QB-oU
private String sFileName; //Saved File's Name Dm@wTt8N(
private int nSplitter; //Count of Splited Downloading File XUD/\MoV
ub"(,k P
s$Il;
public SiteInfoBean() {__Z\D2I
{//nSplitter的缺省值为5 1}E`K#
//default value of nSplitter is 5 JJnZbJti
this("","","",5); SL;\S74
} Z=O2tR
7Q<uk[d0
+uF!.!}
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~Od4( }/G
{ *yuw8
sSiteURL= sURL; K_V44f1f
sFilePath = sPath; @jW_ rj:<
sFileName = sName; e75k-
this.nSplitter = nSpiltter; (89NK]2x
{IeW~S'&
.+G),P)
} U*ZP>Vv
Ae,-.xJ
&bx;GG\<4
public String getSSiteURL() 8wz4KG3SK
{ %h**L'~``
return sSiteURL; n:?fv=9n
} ^4LkKYMS
F|*{Ma
R v9?<]
public void setSSiteURL(String value) a;Ic!:L
{ H/_R!G8\
sSiteURL = value; d7A08l{
} uQN8/Gy*J
-ob_]CKtJ~
ZdEeY|j
public String getSFilePath() a1p:~;f}[
{ DBl.bgf
return sFilePath; 0fvQPs!O
} ,P^pDrc
@18"o"c7j
#&.&Uu$
public void setSFilePath(String value) d:0RDK-}s
{ AElx #`T
sFilePath = value; [L1pDICoy
} >n@?F[Y
oK h#th
pN<wO1\9
public String getSFileName() lgZ3=h
{ )5lo^Qb
return sFileName; Lj"~6l`)
} xm>RLx}9
uROt h_/
rE"`q1b#
public void setSFileName(String value) ZVpMR0!
{ [ADr _
sFileName = value; ;YxQo o>
} v*5n$UFV
W|@EKE.k
/%Bc*k=ox
public int getNSplitter() sk!v!^\_r
{ Wy%q9x]}
return nSplitter; 9+.0ZP?
} B^Q\l!r
zIWw055W
krZ J"`
public void setNSplitter(int nCount) v'B++-%
{ o)KF+[^
nSplitter = nCount; QBa1c-Y
} CzxU @
} .-+_>br~
v?rjQ'OP
gZgb-$b
/* *L8Pj`zR
**Utility.java Q44Pg$jp
*/ ks7g*; 3{@
package NetFox; PYqx&om
4VPL -":6
< vU<:S
public class Utility { o|8 5<~`
s)"C~w^
D%umL/[]
public Utility() D;)Tm|XizW
{ ^~(vP:
K1Nhz'^=D
&R/)#NAp
} w4pU^&O
I!.o&dk
//线程睡眠 &|u
public static void sleep(int nSecond) 7]YLe+Ds
{ <3z]d?u
try{ y]9 3z!#Z
Thread.sleep(nSecond); m/n_e g
} dg 0`0k
catch(Exception e) z %` \p
{ T%K(opISc(
e.printStackTrace (); b9[;qqq@'
} qSj2=dlW
} _*6nTSL
r_T\%
//日志 ZAzn-n
public static void log(String sMsg) T F&xiL^
{ Z}.N4 /
System.err.println(sMsg); wly#|
} |$#u~<r_ w
Ixg.^>62
KDgJ~T
public static void log(int sMsg) F{ J>=TC
{ Ae:(_UJz
System.err.println(sMsg); -Ep cX!i
} npg.*I/>
} g5R2a7
"JAYTatO7H
/HgdTyR)
/* /ZZo`
**TestMethod.java >|!F.W
*/ E#r6e+e1Q%
package NetFox; %TdZ_
314PcSc
rH8^Fl&jT
public class TestMethod { G>&=rmK"
ZO{uG(u
zx'G0Z9]
public TestMethod() -EFtk\/
{ ///xx/weblogic60b2_win.exe 64>E|w
try{ jDIO,XuF
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |Y"q. n77
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5b3Wt7
SiteFileFetch fileFetch = new SiteFileFetch(bean); <~t38|Ff@
fileFetch.start(); H1rge<
} Jf@M>BT^A
catch(Exception e){e.printStackTrace ();} Z+)R%Z'aL
<",4O
4m$nVv
} [jve |-v=
w-};\]I
s/UIo^m
public static void main(String[] args) +I#4+0f
{ : m$cnq~h
new TestMethod(); X|t?{.p
} sXOGIv
} 7g_:Gv~v
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