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)); \0veld
} a@S{A5j
for(int i=0;i<nEndPos.length-1;i++) lyD=n
{ U#G<cV79
nEndPos = nStartPos[i+1]; 2!_DkE
} 8F K%7\V
nEndPos[nEndPos.length-1] = nFileLength; %M,^)lRP
} 6z5wFzJv?q
} F};T<#
P84=.*>
%-KgR
//启动子线程 w `nm}4M
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; T'ei>]y]
for(int i=0;i<nStartPos.length;i++) &n'@L9v81
{ IhHKRb[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RT. %\)))
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Alk+MwjR
nStartPos,nEndPos,i); `t"7[Zk
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZmDM=qN
fileSplitterFetch.start(); D(WdI
} 9~J#> C0}
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N9#5 P!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); J9/EJ'My
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Urz9S3#\
nEndPos = " + nFileLength); < V*/1{
// fileSplitterFetch[nPos.length-1].start(); Y?6}r;<
^;sE)L6
bA1O]:`
//等待子线程结束 >a;LBQ0
//int count = 0; )UtK9;@"
//是否结束while循环 I|l5e2j
boolean breakWhile = false; 9vP#/-g
tlM >=s'T
TkR#Kzv380
while(!bStop) cGyR_8:2cv
{ Nwo*tb:
write_nPos(); +|--}iE5n
Utility.sleep(500); X%$1%)C9
breakWhile = true; vaLP_V
vScEQS$>
n/{ pQ&B
for(int i=0;i<nStartPos.length;i++) 29^(weT"]
{ e'sS",o*
if(!fileSplitterFetch.bDownOver) ?kK3%uJy&
{ o)GesgxFa5
breakWhile = false; x];i? 4
break; 6:q,JB@i
} YwS/O N
} &Oc `|r*
if(breakWhile) fRb
break; /:v}Ni"6nF
!sp`oM
q"5\bh1"
//count++; 'ka}x~EF
//if(count>4) rd;E /:`5
// siteStop(); *'*,mfk[
} "(iDUl
au]W*;x
/BN=Kl]
System.err.println("文件下载结束！"); }G "EdhSl
} 8>9MeDE
catch(Exception e){e.printStackTrace ();} $DaQM'-
} :r2d%:h%2
RG=i74a
voFg6zoV_
//获得文件长度 ]T{v~]7:{
public long getFileSize() JAM]neKiX
{ dOK]Su
int nFileLength = -1; KF1Zy;
try{ }lXor~_i
URL url = new URL(siteInfoBean.getSSiteURL()); DS9-i2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2r!- zEV
httpConnection.setRequestProperty("User-Agent","NetFox"); qnb/zr)p
#Cx#U"~G`
Z^BZH/I?
int responseCode=httpConnection.getResponseCode(); +^jm_+
if(responseCode>=400) J7sH]
{ e _(';Lk
processErrorCode(responseCode); -Mf-8zw8G
return -2; //-2 represent access is error ^oYRBEIJH
} 0|]d^bo
LqXVi80
3ZN\F
String sHeader; ]9~Il#
P+y XC^ ,
g{ ;OgS3>
for(int i=1;;i++) ,:#h;4!VRF
{ a*t @k*d_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;n.h!wmJ}
//Utility.log(in.readLine()); cNikLd~?A
sHeader=httpConnection.getHeaderFieldKey(i); *Z\AO'h=Z
if(sHeader!=null) Ly/
{ 0176
if(sHeader.equals("Content-Length")) @FZ_[CYg
{ ~N/a\%`
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *&I _fAh]
break; >K&chg@Hv
} .'.bokl/
} |26[=_[q
else h:|BQC
break; :0ltq><?
} ll[&O4.F
} cq5^7.
catch(IOException e){e.printStackTrace ();} yJ`{\7Uqg
catch(Exception e){e.printStackTrace ();} y>:U&P^
`A5n6*A7
CbXSJDs
Utility.log(nFileLength); [c -|`d^
s(ap~UCOw
h6IO;:P)
return nFileLength; 2.=G
} >$yA ,N
cW_l|
q!+:zZu
//保存下载信息（文件指针位置） ]NtBP
private void write_nPos() k7{|\w%
{ c<lEFk!g
try{ _mk@1ft
output = new DataOutputStream(new FileOutputStream(tmpFile)); vC^{,?@
output.writeInt(nStartPos.length); a\~118 !
for(int i=0;i<nStartPos.length;i++) yye5GVY$
{ p] N/]2rR
// output.writeLong(nPos); @h_ bXo
output.writeLong(fileSplitterFetch.nStartPos); ,`OQAJ)>
output.writeLong(fileSplitterFetch.nEndPos); 4;>HBCM4-
} oX*;iS X
output.close(); lWd@
} ,jtaTG.>
catch(IOException e){e.printStackTrace ();} +Wgfxk'{
catch(Exception e){e.printStackTrace ();} \YFM5l;IU
} OHW|?hI=[
]5K(}95&'
<`G-_VI
//读取保存的下载信息（文件指针位置） +S+=lu _
private void read_nPos() FC~%G&K/q^
{ FV3[7w=D\
try{ :>o0zG[;f
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); X$@qs9?)^
int nCount = input.readInt(); Ryygq,>VD.
nStartPos = new long[nCount]; )FmIL(vu
nEndPos = new long[nCount]; @H3x51PT(m
for(int i=0;i<nStartPos.length;i++) 49<t2^1q
{ )y Zr]
nStartPos = input.readLong(); 6|{&7=1t
nEndPos = input.readLong(); yGSZ;BDW:K
} VXlAK(
input.close(); lzz;L z
} )v11j.D
catch(IOException e){e.printStackTrace ();} ms!|a_H7r
catch(Exception e){e.printStackTrace ();} ywkRH
} m2YsE j7
h{H*k#>
-'L~Y~'.
private void processErrorCode(int nErrorCode) ,Vo[mB
{ H3`.Y$z
System.err.println("Error Code : " + nErrorCode); ~'0ZW<X.
} )n1[#x^I
F|R7hqf
<2]D3,.g.
//停止文件下载 _ WPt zL
public void siteStop() $uJc/
{ $duT'G, -
bStop = true; =yM%#{t&W
for(int i=0;i<nStartPos.length;i++) g oyQ',+
fileSplitterFetch.splitterStop(); S("dU`T?
~IWdFUKk
'ey62-^r6
} #B6f{D[pI
} #`f{\
//负责部分文件的抓取 ~b!la
**FileSplitterFetch.java W}2!~ep!
*/ 6O.kKhk
package NetFox; (9TSH3f?
Z h9D^I
LH=^3Gw
import java.io.*; diVg|Z3T
import java.net.*; H?a $o(
"frioi`a2
$$W2{vr7+
public class FileSplitterFetch extends Thread { '1xhP}'3)
o)n)Z~
I"x~ 7
String sURL; //File URL A>e-eD xi
long nStartPos; //File Snippet Start Position |5:2?S2R
long nEndPos; //File Snippet End Position o1?-+P/
int nThreadID; //Thread's ID ;ND[+i2MN
boolean bDownOver = false; //Downing is over ^OX}y~'
boolean bStop = false; //Stop identical .T ,HtHe
FileAccessI fileAccessI = null; //File Access interface t+q;}ZvG
;hV|W{=w
MEJX5qG6m
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Lccy~2v>
{ *RVCz|0%w
this.sURL = sURL; *5*#Z~dut8
this.nStartPos = nStart; fA?v\'Qq/
this.nEndPos = nEnd; 9E8&~y
nThreadID = id; #"?pY5 ("
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ' Q(kx*;
} surNJ,)
9wGsHf8]
;H`@x Lv*
public void run() S w%6-
{ Jc}6kFgO6
while(nStartPos < nEndPos && !bStop) @1gURx&2_
{ \>}#[?y
zS|4@t\__
Njr;Wa.r+
try{ N-&ZaK
URL url = new URL(sURL); ]jn1T^D'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <6Y;VH^_
httpConnection.setRequestProperty("User-Agent","NetFox"); &Xh>w(u
String sProperty = "bytes="+nStartPos+"-"; 2 'D,1F
httpConnection.setRequestProperty("RANGE",sProperty); |r,})o>
Utility.log(sProperty); x{zZ%_F
YcclO
0'.z|Jg=
InputStream input = httpConnection.getInputStream(); _u u&?<h
//logResponseHead(httpConnection); DO~[VK%|
)?{!7/H F@
WQze|b%
byte[] b = new byte[1024]; Y<(7u`F
int nRead; }7b{ZbDI
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) C4`&_yoP4-
{ ai1;v@1
nStartPos += fileAccessI.write(b,0,nRead); G3+e5/0
//if(nThreadID == 1) FE{c{G<
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `w`N5 !
} <nG}]Smd7
DR3om;Uk
"v`q%(TA
Utility.log("Thread " + nThreadID + " is over!"); mAGD qz>f
bDownOver = true; lo'#dpt<
//nPos = fileAccessI.write (b,0,nRead); Mp!1xx
} aXQAm$/ >
catch(Exception e){e.printStackTrace ();} $BgaLJs/O
} j6~`C ?(
} #a~BigZ[G
}cGILH%
z;2& d<h
//打印回应的头信息 ?V+\E2
public void logResponseHead(HttpURLConnection con) ;S$
{ .d[^&<^
for(int i=1;;i++) dTCLE t.
{ rr\9HA
String header=con.getHeaderFieldKey(i); bma.RCyY<
if(header!=null) 3+d^Bpp4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); P]y{3y:XxM
Utility.log(header+" : "+con.getHeaderField(header)); <YEKbnw$o
else O-)[!8r
break; wb(S7OsMO
} s_RK x)w@
} dhxzW@'nIL
}~PG]A
4g2`[<S
public void splitterStop() Rx"+i0
{ $6J22m!S4n
bStop = true; lxgfi@@+h
} ~MC5rOA
59SL mj
Bhx.q,X
} mLkp*?sfC
'jE/Tre^
(jhi<eV
/* KWD{_h{R
**FileAccess.java yHC[8l8%
*//文件访问(定位，写) WbhYGcRy
package NetFox; xg^%8Ls^
import java.io.*; l<4P">M!.
0<uLQVoR2n
xr@;w8X`^
public class FileAccessI implements Serializable{ iRkUL]H@&
n{L^W5B
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 v@SHR0
RandomAccessFile oSavedFile; 5{+2#-
long nPos; }:{ @nP
YT'V/8US
qrj f
public FileAccessI() throws IOException j7a}<\
{ _unoDoB
this("",0); cpw=2vnD
} ;Gn>W+Ae M
4I2:"CK06
$8&Y(`
public FileAccessI(String sName,long nPos) throws IOException NvTK7? v
{ 8rlf9m
oSavedFile = new RandomAccessFile(sName,"rw"); lc~c=17
this.nPos = nPos; E^5
oSavedFile.seek(nPos); mS;WNlm\
} -}j(_]t
)p;t '*]
"K9[P:nw
public synchronized int write(byte[] b,int nStart,int nLen) Wf5;~RJC?
{ 8mRZ(B>% X
int n = -1; oHv.EO
try{ :eD-'#@$u
oSavedFile.write(b,nStart,nLen); Hf1b&8&:K
n = nLen; f_LXp$n
} n/*" 2
catch(IOException e) qa@;S,lp
{ SDSP4W5
e.printStackTrace (); tq~f9EvC
} GhcH"D%-
PZ'|)
eg?p)|
return n; fr04nl
} ;vPFRiFK
[4YRyx&:++
No[9m_
} q&&"8.w-
U&Atgv
U=j`RQ 9,
/* "+qZv(
**SiteInfoBean.java >FHx],
*/ ZlE=P4`X:
package NetFox; :8}Qt^p
Tmu2G/yi
G,P k3>I'
public class SiteInfoBean { *\}$,/m['
>d"\
i?@7>Ca
private String sSiteURL; //Site's URL Evg#sPu\
private String sFilePath; //Saved File's Path KVEc:<|x
private String sFileName; //Saved File's Name _99 +Vjy
private int nSplitter; //Count of Splited Downloading File h:C:opa-=
|x&4vHXR0
MNTVG&h
public SiteInfoBean() 33eOM(`D[
{//nSplitter的缺省值为5 a;U)#*(5|v
//default value of nSplitter is 5 JgP%4)]LV
this("","","",5); A/}[Z\C
} }2*qv4},!
!blGc$kC
L[Y$ `e{zd
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) zPHx\z"
{ i,Z-UA|f=T
sSiteURL= sURL; .=G3wox3
sFilePath = sPath; :@E^oNKa0
sFileName = sName; <6hs<qXqi
this.nSplitter = nSpiltter; l?m 3*
<_*5BO
5&L*'kV@
} 'x?|tKzd
8dt=@pwx&
PGxv4(%
public String getSSiteURL() y0O e)oP
{ %G6x\[,
return sSiteURL; l& sEdEA
} %z[=T@
1B&XM^>/
sRcS-Yw[S
public void setSSiteURL(String value) o.|36#Fa
{ o>d0R w4h
sSiteURL = value; ?/hS1yD;
} x#5[i;-c
[9~EH8
]w]BKpU=
public String getSFilePath() F2Ny=H&G
{ O5+Ah%
return sFilePath; }z\t}lven
} 9h-S,q!
:nqDX
/RhM6N
public void setSFilePath(String value) jY/(kA]}
{ 0v1~#KCm
sFilePath = value; +9t{ovF?L
} YbWz!.WPe
`-b{|a J
aYpc\jJ
public String getSFileName() C9k"QPE
{ V8o, e
return sFileName; {IBbN05 ;
} 5RO6YxQ
).u>%4=6
/Hm/%os
public void setSFileName(String value) /J!hKK^k
{ &pz`gna
sFileName = value; e,#5I(E
} HD$`ZV
A93(} V7I
LSXsq}
public int getNSplitter() 5OOXCtIKf
{ ,?%Y*?v
return nSplitter; )ytP$,r![S
} :AuKQ`c
P&Xy6@%[Z
DSp~k)
public void setNSplitter(int nCount) :c )R6=v
{ UaQW<6+
nSplitter = nCount; e9S*^2;
} \fUVWXv
} B"*PBJuOA
ga;t`5+d
F60m]NUM)c
/* KqaEHL
**Utility.java K@osD7-
*/ =R9`to|
package NetFox; _XrlCLp: d
7VkjnG^!:
!>K=@9NC|.
public class Utility { Dp} $q`F[
~\u>jel
!@ AnwV]
public Utility() F<2gM#jLB
{ O0pXHXSAL
*8%uXkMm
7s:cg
} 2AxKB+c1`
a~-k} G5
//线程睡眠 %^"i\-*|S
public static void sleep(int nSecond) 4m~p(r
{ kqC7^x
try{ pMUUF5
Thread.sleep(nSecond); y=SpIbn{
} UK@hnQU8`
catch(Exception e) EW]8k@&g
{ 6Ol)SQE,
e.printStackTrace (); !@+4&B=
} ~_-+Q=3
} {K/xI
i5*/ZA_
//日志 !g~u'r'1
public static void log(String sMsg) #Wv8+&n
{ YsTF10
System.err.println(sMsg); Ac +fL
} QNj6ETB-d
sN1I+X
poi39B/Vt
public static void log(int sMsg) Ipow Jw^
{ hrfSe$8
System.err.println(sMsg); &&96kg3
} '0qKb*
} S^i<_?nwg
v:9Vp{)
MP Q?Q]'
/* LN'})CI8m
**TestMethod.java 6?0QzSpfC#
*/ cI<T/~P
package NetFox; c+1<3)Q<
eE0nW+i
g9=O<u#
public class TestMethod { #'y^@90R
:+fW#:
uH)v\Js
public TestMethod() -li;w tCS
{ ///xx/weblogic60b2_win.exe >+ Im:fD
try{ f+QDjJ?z
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7zXX& S
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); h~&5;
SiteFileFetch fileFetch = new SiteFileFetch(bean); DwXSlsN3v
fileFetch.start(); 7 /DDQ
} xw1n;IO4
catch(Exception e){e.printStackTrace ();} U,~Z2L
sbFA{l3
p,OB;Ncf/
} PV/hnVUl
&=-{adm
G\r>3Ys
public static void main(String[] args) t@BhosR-
{ c 9zMI
new TestMethod(); F4&`0y:
} 'd<1;Ayw
} FK,YVY
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