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)); . {vMn0c
} VXnWY8\
for(int i=0;i<nEndPos.length-1;i++) !CdF,pd/)m
{ t2Px?S?
nEndPos = nStartPos[i+1]; TQtHU6
} wBJ|%mc3TA
nEndPos[nEndPos.length-1] = nFileLength; R"yxpw
} ;$67GK
} rvacCwI
P(UY}oU
;\(LovUy6
//启动子线程 CofTTYl
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; lA`qB1x
for(int i=0;i<nStartPos.length;i++) d`,z4_
{ ,A5}HRW%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i#aKW'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), o)GesgxFa5
nStartPos,nEndPos,i); #w@FBFr@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |\Q2L;4C
fileSplitterFetch.start(); YwS/O N
} &Oc `|r*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), HB,?}S#TP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); h$XoR0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `-.6;T}2U
nEndPos = " + nFileLength); "g*`G<W_s
// fileSplitterFetch[nPos.length-1].start(); K 6yD64
;jJ4H+8
I Z|EPzS
//等待子线程结束 <KJ|U0/jGd
//int count = 0; ^u2x26].
//是否结束while循环 CTe!jMZ=
boolean breakWhile = false; }qJ`nN8
e8E'X
XmaRg{22
while(!bStop) S5:&_&R8[
{ 8>9MeDE
write_nPos(); }KYOde@
Utility.sleep(500); >@h#'[z,d
breakWhile = true; 9{}"tk5$h
k8!:`jG
= c1>ja
for(int i=0;i<nStartPos.length;i++) +,g!xv4Q
{ 4M!wm]n/%5
if(!fileSplitterFetch.bDownOver) uzI-1@`
{ XgyLlp;,O
breakWhile = false; Y_6v@SiO
break; MJ$.ST
} oJ tmd}
} ;<*%BtD?
if(breakWhile) ?-~<Vc*
break; }(!rB#bf
^oYRBEIJH
A<^X P-Nrp
//count++; (! 8y~n1
//if(count>4) K,6{c^qf
// siteStop(); P+y XC^ ,
} \mTi@T!&
7|yEf
a*t @k*d_
System.err.println("文件下载结束！"); r7#.DJnN.
} Nobu= Z
catch(Exception e){e.printStackTrace ();} g<ov` bF
} "[rz*[o8I
>5E1y!
;W|GUmADf
//获得文件长度 0_AIKJrL
public long getFileSize() HRJ\H- V
{ 0176
int nFileLength = -1; @FZ_[CYg
try{ @LFB}B
URL url = new URL(siteInfoBean.getSSiteURL()); t&p I
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R)4,f~@"
httpConnection.setRequestProperty("User-Agent","NetFox"); >Q'*~S@v3
#C'E'g0
*VHWvj
int responseCode=httpConnection.getResponseCode(); :0ltq><?
if(responseCode>=400) ll[&O4.F
{ cq5^7.
processErrorCode(responseCode); 9KB}?~Nx4
return -2; //-2 represent access is error $=ESY>MO
} ^O=G%de
7SN61)[m
acar-11_o/
String sHeader; \3]O?'
(>Nwd^
:xTm-L
for(int i=1;;i++) }I MV@z B
{ ;y{(#X#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?S9vYaA$
//Utility.log(in.readLine()); k ]T
sHeader=httpConnection.getHeaderFieldKey(i); .XkD2~;
if(sHeader!=null) +sTPTCLE
{ =y(*?TZH
if(sHeader.equals("Content-Length")) yye5GVY$
{ p] N/]2rR
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); @h_ bXo
break; `>b,'u6F
} 0rQr#0`
} !G6h~`[
else l@1=./L?
break; ._t1eb`m{
} 4\nGWi{2
} fFoZ!H
catch(IOException e){e.printStackTrace ();} `KE]RTq
catch(Exception e){e.printStackTrace ();} I<XYLe[_S
C@[U:\
*z#du*f[
Utility.log(nFileLength); ZR-64G=L,
UCkV;//.
3Agyp89}Q
return nFileLength; %C@p4
} p@Cas
KT*>OYI
A0RSNAM
//保存下载信息（文件指针位置） FzP1b_i
private void write_nPos() @/ nGc9h
{ K3UN#G)U
try{ C@\5%~tW+
output = new DataOutputStream(new FileOutputStream(tmpFile)); s[dIWYs#
output.writeInt(nStartPos.length); [k(b<'
for(int i=0;i<nStartPos.length;i++) KF5r?|8M
{ ywkRH
// output.writeLong(nPos); m2YsE j7
output.writeLong(fileSplitterFetch.nStartPos); h{H*k#>
output.writeLong(fileSplitterFetch.nEndPos); -'L~Y~'.
} ,Vo[mB
output.close(); ~)`\j
} @$ju Qm
catch(IOException e){e.printStackTrace ();} GD'Z"rhI
catch(Exception e){e.printStackTrace ();} ~t/i0pKq.
} qX; F+~
l(-"rE
`@WJ_-$#
//读取保存的下载信息（文件指针位置） g]c6_DMfb1
private void read_nPos() $o;c:Kh$$
{ hQ!59
try{ j_~mP>el)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i7v=o#
int nCount = input.readInt(); '*&dP"
nStartPos = new long[nCount]; {o5^nd
nEndPos = new long[nCount]; ;"ESN)*|i
for(int i=0;i<nStartPos.length;i++) ]NI CQ9
{ <5 OUk
nStartPos = input.readLong(); nT+ZSr
nEndPos = input.readLong(); D`mr>-Y
} q,%Fvcmx+e
input.close(); /3tErc'
} olA+B
catch(IOException e){e.printStackTrace ();} C^;8M'8z0
catch(Exception e){e.printStackTrace ();} r\FZ-gk}Q
} = &?&}pVF
Q<g>WNb
/Hq
private void processErrorCode(int nErrorCode) ~tV7yY|zr
{ A>e-eD xi
System.err.println("Error Code : " + nErrorCode); Rm79mh9
} } XhL`%
2eeFaFif
xGbq,~_r
//停止文件下载 ^,t@HN;gA
public void siteStop() GUqG1u z9
{ Rg\4#9S JF
bStop = true; W,[QK~
for(int i=0;i<nStartPos.length;i++) *)`PY4zF
fileSplitterFetch.splitterStop(); tg==Qgz
5GgH6
]4V1]
} 9E8&~y
} #"?pY5 ("
//负责部分文件的抓取 `?WN*__["
**FileSplitterFetch.java S:`Gi>D
*/ TXXG0 G
package NetFox; E{e
?daxb
&7>]# *
import java.io.*; Zlh 2qq
import java.net.*; s3yGL
/\uopa
={ -kQq
public class FileSplitterFetch extends Thread { jb,a>9]p
4b;*:C4?
]h' 38W
String sURL; //File URL _u u&?<h
long nStartPos; //File Snippet Start Position 3N+B|WrM
long nEndPos; //File Snippet End Position j[FB*L1!D
int nThreadID; //Thread's ID Bos} `S![
boolean bDownOver = false; //Downing is over U#K4)(C
boolean bStop = false; //Stop identical ~o|sma5.
FileAccessI fileAccessI = null; //File Access interface 1cMLl6Bp>
=EM<LjO
oYA"8ei=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException g\8B;
{ 5}Ge
this.sURL = sURL; tc)Md]S
this.nStartPos = nStart; 8!3q:8y8
this.nEndPos = nEnd; |4P8N{ L>O
nThreadID = id; rl~Rbi
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~TXu20c
} rtQ{
UBM#~~sM
u0sN[<
public void run() $gz8! f?
{ DEhR\Z!
while(nStartPos < nEndPos && !bStop) Ta/zDc"e
{ }cGILH%
z;2& d<h
?V+\E2
try{ 5S!j$_(
URL url = new URL(sURL); :p@jslD
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V9}\0joM
httpConnection.setRequestProperty("User-Agent","NetFox"); eq8faC5
String sProperty = "bytes="+nStartPos+"-"; km5gO|V>m
httpConnection.setRequestProperty("RANGE",sProperty); SqRM*Cf=
Utility.log(sProperty); 2-N7%]h
<YEKbnw$o
O-)[!8r
InputStream input = httpConnection.getInputStream(); wb(S7OsMO
//logResponseHead(httpConnection); s_RK x)w@
E<u(Yw6=
}fkdv6mz
byte[] b = new byte[1024]; &{glwVKV
int nRead; &\~*%:C
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Z:>3AJuS_
{ ~"vS$>+
nStartPos += fileAccessI.write(b,0,nRead); "(p/3qFY
//if(nThreadID == 1) 7kA+F+f
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); iHf):J?8 y
} @M-Q|
K0C"s'q
k}E_1_S(
Utility.log("Thread " + nThreadID + " is over!"); 0F![<5X
bDownOver = true; 4guR8 elM
//nPos = fileAccessI.write (b,0,nRead); t\ z@k9
} &=M4Z/Ao
catch(Exception e){e.printStackTrace ();} .o]I^3tfc
} Cg~1<J?2
} cr]b #z
ni2 [K`
dMsS OP0E
//打印回应的头信息 Bsg^[~jWJu
public void logResponseHead(HttpURLConnection con) F:#5Edo}A
{ 8(y%]#n
for(int i=1;;i++) x0{B7/FN
{ zh=0zJ
String header=con.getHeaderFieldKey(i); @6+_0^
if(header!=null) dqQJC qc!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8d8jUPFQ
Utility.log(header+" : "+con.getHeaderField(header)); _=`DzudE
else W.cc!8
break; $8&Y(`
} _%Xp2`m
} -zJV(`
{{_v.d~1
4VeT]`C^h
public void splitterStop() ,ZrR*W?iF
{ )CE]s)6+2
bStop = true; !O`j
} p<0=. ~
-~xQ@+./
ia;osqW
} na9YlJ\
\<xo`2b
)16+Pm8
/* 5Uy*^C7M^
**FileAccess.java us1$
*//文件访问(定位，写) <"`f!k#[
package NetFox; Ci4c8
import java.io.*; J@<f*
%(6+{'j~#
aZ{l6
public class FileAccessI implements Serializable{ eFf9T@
5izpQ'>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 m*jE\+)=^
RandomAccessFile oSavedFile; T]1.":
long nPos; )=#Js<&3:
xZ%3e sp
K8-1?-W
public FileAccessI() throws IOException R1Q,m
{ U,T#{
this("",0); iR{@~JN=)
} 4G;KT~Cgb
|T"j7
+/[Rvh5WZ
public FileAccessI(String sName,long nPos) throws IOException ZrNH:Z:5
{ 3Rsrb
oSavedFile = new RandomAccessFile(sName,"rw"); \r{wNqyv
this.nPos = nPos; ThW9=kzQW
oSavedFile.seek(nPos); mAW(j@5sp
} aQY.96yo
_dAn/rj
lH/"47
public synchronized int write(byte[] b,int nStart,int nLen) [N%InsA9k
{ Ez-AQ'
int n = -1; ;g+fY6
try{ '-I\G6w9
oSavedFile.write(b,nStart,nLen); tBZ?UAe;
n = nLen; lFIaC}
} #hs&)6Sf
catch(IOException e) QhRj*,
{ <6hs<qXqi
e.printStackTrace (); nTs\zikP
} roG<2i F
b5jD /X4
| a i#rU
return n; XH*(zTd(?
} 1>OU~A"
U61 LMH
Zm++5b`W/[
} [h' 22W
b">"NvlB
AA ~7"2e
/* Lp}V 94xT
**SiteInfoBean.java !H c6$
*/ &6Lh>n(
package NetFox; ^b$G.h{o!E
Xm(#O1Vm(l
%t1Z!xv_
public class SiteInfoBean { 4$N,|bt
/FW$)w2{j
2Q%M2Ua
private String sSiteURL; //Site's URL H|j]uLZ
private String sFilePath; //Saved File's Path '|v<^EH
private String sFileName; //Saved File's Name zT/woiyB`
private int nSplitter; //Count of Splited Downloading File =c#mR" 1
|t3}>+"?z
g}hNsU=$5~
public SiteInfoBean() +gBDE:
{//nSplitter的缺省值为5 qQo*:3/];
//default value of nSplitter is 5 yU7XX+cB7
this("","","",5); ND=JpVkvZ?
} F &5iA\
j1+I_
C9k"QPE
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \7xc*v [
{ yEJ3O^(F
sSiteURL= sURL; (~F}O
sFilePath = sPath; J &=5h.G$
sFileName = sName; :*|So5fs
this.nSplitter = nSpiltter; 6fBA#Kb
g%m-*v*
<.BY=z=H
} `2V{]F
8<Yv:8%B6
> 9z-/e
public String getSSiteURL() vKdS1Dn1
{ g?}h*~<b
return sSiteURL; RCK*?\m5
} Y}yh6r;i
3w[uc~f
|@R/JGB^
public void setSSiteURL(String value) &lzCRRnvt
{ UN;U+5,t
sSiteURL = value; TOSk+2P
} o2]Np~`g,
94*MRn1E
;r]! qv:
public String getSFilePath() 69uDc
{ /Q#eP m
return sFilePath; l 8GAZ*+
} KiC,O7&<
c1*^ \
"8(8]GgYx
public void setSFilePath(String value) XIM?$p^
{ YxU->Wi]G
sFilePath = value; ~\u>jel
} Z~|%asjFE
~WB-WI\
#q&Nd2y
public String getSFileName() w`#9Re
{ UA0( cK
return sFileName; k4:=y9`R}$
} bsI?=lO
LT,zk)5
{ M[iYFg=
public void setSFileName(String value) B4m34)EOE
{ %,Y^Tp
sFileName = value; R \y qM;2
} S!JLy&@
+f_3JL$
V{qR/
public int getNSplitter() =G'J@[d{d
{ 1mfB6p1Z(
return nSplitter; 0PUSCka'6
} C'sA0O@O
$Nj'_G\}
/>PH{ l
public void setNSplitter(int nCount) 5g9K|-
{ Q5Mn=
nSplitter = nCount; Di$++T8"
} [$\VvRu%
} :FS~T[C;
~"R;p}5"
ukD:4sv
/* 2Aa
**Utility.java kCoEdQ_
*/ `j.-hy>s
package NetFox; 8D^ iQBA
|hu9)0P
F22]4DLHO
public class Utility { H}1XK|K3#H
"#%9dWy
k>\s6
public Utility() 6?0QzSpfC#
{ cI<T/~P
c+1<3)Q<
eE0nW+i
} DPl&e-`
7Uh/Gl
//线程睡眠 D;DI8.4`N
public static void sleep(int nSecond) dFnu&u"
{ P>*`<$FR
try{ `DP4u\6_
Thread.sleep(nSecond); {E1^Wn1M
} h61BIc@>
catch(Exception e) U owbk:
{ GM@0$
e.printStackTrace (); ;|Rrtf9
} ?SoRi</1
} hBW,J$B
p;2NO&
//日志 [Ue"#w
public static void log(String sMsg) :&O6Y-/B
{ @Y&(1Wl
System.err.println(sMsg); wF['oUwHH
} $\nAGmp@
t@BhosR-
c 9zMI
public static void log(int sMsg) k3e?:t 9
{ <r8s=<:
System.err.println(sMsg); ~_4$|WKl
} ~NwX,-ri
} >t $^U
lXrAsm$
.W0;Vhw"
/* *U|2u+| F
**TestMethod.java 2&:w_KJ
*/ E uk[ @1
package NetFox; +H3;{ h9,
!O/(._YB`
qMcOSZ%8J
public class TestMethod { 3Ett9fBd
3*<~;Z' z4
EwOi` g
public TestMethod() E#M4{a1
{ ///xx/weblogic60b2_win.exe V#d8fRm
try{ 6vZ.CUK9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /q6 ^.>b
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); um mkAeWb
SiteFileFetch fileFetch = new SiteFileFetch(bean); _n3"
fileFetch.start(); E&2mFg
} FZJ sZeO
catch(Exception e){e.printStackTrace ();} "]1|%j
2c8e:Xgv
.h>tef
} 7?~*F7F
4-\gha
vsCy?
public static void main(String[] args) &UoQ8&
{ ;rJ/Diz!g
new TestMethod(); Xx=c'j<
} :|E-Dx4F6H
} P}$DCD<$U
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