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)); x@ =p
} >fC&bab
for(int i=0;i<nEndPos.length-1;i++) lD0p=`.
{ NN4Z:6W5
nEndPos = nStartPos[i+1]; P#A,(Bke3
} !4p{b f
nEndPos[nEndPos.length-1] = nFileLength; Kki(A4;7F
} JT 7WZc)
} l+Wux$6U
$J6 .0O
pz^S3fy
//启动子线程 /4r2B.91O
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {vD$odi
for(int i=0;i<nStartPos.length;i++) }_lG2#Ll5
{ q2%cLbI F
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {-5)nS^_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :I#.d7`uk
nStartPos,nEndPos,i); eCI'<^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t!\aDkxo %
fileSplitterFetch.start(); w[z=x
} :%gc Sm
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), EE'2<"M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #4AU&UM+i
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", q[Ai^79
nEndPos = " + nFileLength); aqSOC(jU
// fileSplitterFetch[nPos.length-1].start(); oRbWqN`F.
nFni1cCD
&eV5#Ph
//等待子线程结束 ["nWIs[h
//int count = 0; U4d7-&U
//是否结束while循环 dC6>&@ VX
boolean breakWhile = false; I!/EQO|
%E%=Za
.w4|$.H
while(!bStop) z_'^=9m
{ Qy:yz
write_nPos(); s4Ja y!A
Utility.sleep(500); +Ug &
breakWhile = true; x;[)#>.'
:3M,]W]
|co#X8J
for(int i=0;i<nStartPos.length;i++) %/2 ` u
{ `*U@d%a
if(!fileSplitterFetch.bDownOver) e,OXngC
{ r8(oTx
breakWhile = false; 3Y P! B=
break; C6gSj1
} 6O/L~Z*t
} ~;(\a@ _
if(breakWhile) cEHpa%_5
break; IEm?'o:
u/W{JPlL
R V#w0 r
//count++; 7b1 yF,N
//if(count>4) Hl$qmq
// siteStop(); Q^{TcL8
} g(P7CX+y
/,I?"&FWc
u4lM>(3Y}
System.err.println("文件下载结束！"); ^fKKsfIf
} .yF-<Y
catch(Exception e){e.printStackTrace ();} n*GB`I*g
} MO~T_6
ywm"{ U?8
7UBW3{d/u5
//获得文件长度 -F`gRAr-
public long getFileSize() .x$V~t
{ E`N`
int nFileLength = -1; k8E2?kbF
try{ uhq6dhhR
URL url = new URL(siteInfoBean.getSSiteURL()); 9ZOQNN<ex
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _ (b4|hJ'
httpConnection.setRequestProperty("User-Agent","NetFox"); Wda?$3!^q
-AnJLFY
_Nh])p-
int responseCode=httpConnection.getResponseCode(); oxFd@WV5
if(responseCode>=400) 70avr)OM
{ J*g<]P&p0
processErrorCode(responseCode); 6 w!qZ4$
return -2; //-2 represent access is error ="T}mc
} i.9}bw 9u@
';eAaDM
.dzw5R&
String sHeader; T>|+cg
nILUo2e~
6+sz4
for(int i=1;;i++) |vi=h2*
{ v2|zIZ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }!g$k $y
//Utility.log(in.readLine()); 4-O.i\1q
sHeader=httpConnection.getHeaderFieldKey(i); VIWH~UR)&!
if(sHeader!=null) mmFcch$Jv
{ )cN=/i
if(sHeader.equals("Content-Length")) 1 =?pL$+G
{ ;Qd'G7+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); H"+|n2E^
break; H|s Iw:
} W*H%\Y:N
} j.Y!E<e4]
else =[4C[s
break; z@[n?t!7k
} lS;S:- -F
} \U]<HEc^
catch(IOException e){e.printStackTrace ();} [HXd|,~_j-
catch(Exception e){e.printStackTrace ();} -{3^~vW|<
$LR~c)}1I
;|rFP
Utility.log(nFileLength); s/?(G L+Ae
x=JZ"|TE
aS3-A4
return nFileLength; 1b=\l/2
} }8.$)&O$^
L-W*h
_58&^:/^
//保存下载信息（文件指针位置） w#(E+s~}
private void write_nPos() >taT V_,
{ R{4[.
try{ v]drDVJ
output = new DataOutputStream(new FileOutputStream(tmpFile)); yaj1nq!*"
output.writeInt(nStartPos.length); w2"]%WS%
for(int i=0;i<nStartPos.length;i++) 7<Ut/1$MI
{ |b Z 58{}
// output.writeLong(nPos); H_JT"~_2
output.writeLong(fileSplitterFetch.nStartPos); }LBrk0]
output.writeLong(fileSplitterFetch.nEndPos); UL8"{-`_\
} ue *mTMN
output.close(); qB3&F pgW
} ({rescQB
catch(IOException e){e.printStackTrace ();} TAM`i3{D
catch(Exception e){e.printStackTrace ();} 0J)VEMC
} P`hg*"<V
$I@. <J*
x@@k_'~t%
//读取保存的下载信息（文件指针位置） wW/wvC-
private void read_nPos() D>#Jh>4
{ RV5;EM)~[
try{ $<wU>X
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); K0^+2lx
int nCount = input.readInt(); %]DJ-7 xE
nStartPos = new long[nCount]; UJX5}36
nEndPos = new long[nCount]; tIX|oWC$q
for(int i=0;i<nStartPos.length;i++) Wm58[;%LTw
{ 9hwn,=Vh)
nStartPos = input.readLong(); 9NC6q-2
nEndPos = input.readLong(); !ImtnU}
} G_p13{"IM
input.close(); e3&.RrA
} ZONe}tv:
catch(IOException e){e.printStackTrace ();} VN4H+9E
catch(Exception e){e.printStackTrace ();} +>h'^/rAE
} vw q Y;7
5|[\Se#
nG5:H.)
private void processErrorCode(int nErrorCode) Se5jxV
{ 1lUY27MF
System.err.println("Error Code : " + nErrorCode); "6'# L,
} U}`HN*Q.q
DOo34l6#
F[|aDj@q e
//停止文件下载 |w^nCsv
public void siteStop() 0wl31k{
{ r+l3J>:K
bStop = true; } SA/,4/9
for(int i=0;i<nStartPos.length;i++) 0j~C6vp
fileSplitterFetch.splitterStop(); +Y^/0=6h
R75np^
Yg7C"3;Vt
} XAr YmO
} r`'n3#O*
//负责部分文件的抓取 2:S 4M.j
**FileSplitterFetch.java z+@Jx~<i
*/ ~|)'vK8W
package NetFox; 93N:?B9
szb],)|18
~4tu*\P
import java.io.*; j.rJfbE|X
import java.net.*; #$>m`r
F0FF:><
)![?JXf
public class FileSplitterFetch extends Thread { ('p~h-9Vi
,NaNih1
aTY\mKk
String sURL; //File URL ?g'? Ou
long nStartPos; //File Snippet Start Position *e05{C:kS
long nEndPos; //File Snippet End Position "(d7:!%
int nThreadID; //Thread's ID Go_~8w0<
boolean bDownOver = false; //Downing is over )Wm:Ilq
boolean bStop = false; //Stop identical DbkKmv&
FileAccessI fileAccessI = null; //File Access interface pEE.%U
2V#(1Hc!
.),m7"u|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {o[*S%Z"
{ D@>^_cTO24
this.sURL = sURL; `=3:*.T*
this.nStartPos = nStart; h=~TgTv
this.nEndPos = nEnd; 7fJWb)z!k
nThreadID = id; 1e#}+i!a
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $McVK>=
} Hi<5jl
"M.vu}~>
cA4xx^~
public void run() 7].FdjT.
{ W`-AN}C#
while(nStartPos < nEndPos && !bStop) }A%Sx!7~
{ *G#W],~0
~O}LAzGb
/uzU]3KF~
try{ V}kZowWD
URL url = new URL(sURL); G? "6[w/p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0xM\+R~,
httpConnection.setRequestProperty("User-Agent","NetFox"); 0"L_0 t:
String sProperty = "bytes="+nStartPos+"-"; #}W^d^-5t5
httpConnection.setRequestProperty("RANGE",sProperty); =X11x)]F9
Utility.log(sProperty); RscU=oaKi
0)'^vJe
<k&Q"X:"
InputStream input = httpConnection.getInputStream(); }Z_w8+BZ
//logResponseHead(httpConnection); N?h=Zl|
1^zpO~@S
Vn6g(:\w
byte[] b = new byte[1024]; b}9Ry"
int nRead; m. G}#/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1/YWDxo,
{ bi bjFg
nStartPos += fileAccessI.write(b,0,nRead); -qBrJ1*
//if(nThreadID == 1) Vx^+Z,y&QP
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E8~Bp-G)
} !$x9s'D
39QAj&
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Utility.log("Thread " + nThreadID + " is over!"); 8rXu^
bDownOver = true; A-&C.g
//nPos = fileAccessI.write (b,0,nRead); ~ b;%J:
} r-+.Ax4L"
catch(Exception e){e.printStackTrace ();} z17x%jXy
} ^[SQw)*
} MGd 7Ont
&C+pen)Z
nxP>IfSA
//打印回应的头信息 9air"4
public void logResponseHead(HttpURLConnection con) hSq3LoHV
{ sV+/JDl
for(int i=1;;i++) :Uf\r `a9
{ \4`~J@5Y
String header=con.getHeaderFieldKey(i); u+GtH;<;
if(header!=null) >v9 ("
//responseHeaders.put(header,httpConnection.getHeaderField(header)); k"V| f&
Utility.log(header+" : "+con.getHeaderField(header)); bBBW7',[a
else #]'#\d#i
break; %B$~yx3#
} A7|!&fi
} wvum7K{tI
`k/hC
YT6<1-E#
public void splitterStop() `Pv[A
{ R g7 O
bStop = true; s('<ms
} cWSiJr):r
]VY}VALZ
: uglv6
} Rdd[b?
y-gSal
Re**)3#gn
/* b/='M`D}#G
**FileAccess.java "k(Ee
*//文件访问(定位，写) n5X0Gi9
package NetFox; "MD
import java.io.*; %Uj7g>
-ckk2D?
Bkvh]k;F8
public class FileAccessI implements Serializable{ /pZ]:.A
,lLkAd?q
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4i>sOP3 B
RandomAccessFile oSavedFile; K'EGm #I
long nPos; )2KQZMtgm]
Z> jk\[
y-qbK0=X4
public FileAccessI() throws IOException !fXwX3B
{ *P,dR]-m
this("",0); pZx'%-\-T
} u/3 4E=
3>Ts7 wM
sBGYgBu!a
public FileAccessI(String sName,long nPos) throws IOException Ly1V@
{ oqa]iBO
oSavedFile = new RandomAccessFile(sName,"rw"); sf\p>gb
this.nPos = nPos; 47b=>D8
oSavedFile.seek(nPos); g/&`NlD
} 8y5iT?.~vy
3VZeUOxY\W
s*.CJ
public synchronized int write(byte[] b,int nStart,int nLen) XS5*=hv:
{ vs-%J6}G
int n = -1; =l?F_
try{ N6Mo|
oSavedFile.write(b,nStart,nLen); :uE:mY%R
n = nLen; ^W|B Xxo
} 1@*qz\ YY
catch(IOException e) @Omgk=6
{ ;v0M ::
e.printStackTrace (); aV?dy4o$
} zyyt`
$Cw> z^}u
!e?g"5r{Bv
return n; dGf:0xE"
} n4Od4&r
E^z\b *
E_-3G<rt
} >h+[#3vD
K]4XD1n7
ns|)VX
/* )&R^J;W$M1
**SiteInfoBean.java CPssk,q~C
*/ }!=}g|z#|
package NetFox; qP6YnJWl
q 65mR!)
"L'0"
public class SiteInfoBean { ,f ..46G
/,v>w,
wg<UCmfu!
private String sSiteURL; //Site's URL %$K2$dq5
private String sFilePath; //Saved File's Path "LyMw){
private String sFileName; //Saved File's Name #-b0U[,.
private int nSplitter; //Count of Splited Downloading File g.![>?2$8
<BoDLvW>
Y)*5M
public SiteInfoBean() W`HO Q
{//nSplitter的缺省值为5 oG5:]/F
//default value of nSplitter is 5 q3a`Y)aVB
this("","","",5); tHlKo0S$0
} 4 [2^#t[
R%)ZhG*
$2u^z=`b!%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) tmM8YN|
{ thWQU"z4
sSiteURL= sURL; Hgs=qH
sFilePath = sPath; ~Q7)6%
sFileName = sName; u2=gG.
this.nSplitter = nSpiltter; >iefEv\
1T(:bM_t`7
Wez"E2J`
} ?M'_L']N[
x2gnB@t
t Dx!m~[
public String getSSiteURL() 6")co9
{ q:A{@kFq_
return sSiteURL; a%f?OsY
} 'Oyx X
Y{yN*9a79
=Kdd+g!
public void setSSiteURL(String value) Z]-C,8MM
{ pAwmQS\W
sSiteURL = value; C1 qyjlR
} a&yIH;-
fJ"#c<n
-oGJPl{r
public String getSFilePath() +[l52p@a
{ TE+d?
return sFilePath; UO%VuC5B
} dxm_AUM
1QHCX*_
}2qmL$
public void setSFilePath(String value) V'vDXzk\
{ B/#tR^R
sFilePath = value; ofeSGx
} iO^z7Y7
&%YFO'>>}
4}nsW}jCc
public String getSFileName() jn+NX)9
{ /0|niiI
return sFileName; E8]PV,#xY
} 2q2;Uo`"S.
x!rHkuH~
{ bjK(|
public void setSFileName(String value) C:C9swik"5
{ @)0-oa,u+
sFileName = value; 6*@\Qsp615
} "52nT
mG,%f"b0
&=SP"@D
public int getNSplitter() -OLXRc=
{ 5fGUJ[F=
return nSplitter; \VW&z:/*pZ
} .:eNL]2%:
]V9z)uz
.BLF7> M1
public void setNSplitter(int nCount) fneg[K
{ :v/6k
nSplitter = nCount; \<ohe w
} (`0dO8
} @d5G\1(%
z?~W]PWiZ
i*16kdI.
/* 6`LC(Nv%-n
**Utility.java C9oF*{
*/ |JVeW[C
package NetFox; u*R9x3&/5
pa0'\
F+e J9
public class Utility { o!Vs{RRu}
yK"OZ2Mv
~;/\l=Xl
public Utility() ypxqW8Xe
{ ,z}wR::%
o6e6Jw
Q>gU(
} B"O5P>
FrSeR9b
//线程睡眠 [ e4)"A"
public static void sleep(int nSecond) !x9j~D'C`
{ 9g" 1WZ!
try{ &dSw[C#f
Thread.sleep(nSecond); {},rbQ -
} zdA:K25"
catch(Exception e) =l`xXma
{ 1XZ|}Xz
e.printStackTrace (); ]Y[8|HJ8
} v2<roG6.V
} ^ K8JE,
_`!@
//日志 Y=3:Q%X
public static void log(String sMsg) "4FL<6
{ I>b-w;cC
System.err.println(sMsg); hA`>SkO
} fTi,S)F'
Xq&x<td
zE VJ
public static void log(int sMsg) 8uME6]m i
{ sV7dgvVd
System.err.println(sMsg); lj"L Q(^
} P=&Je?
} *VT@
}I7/FqrD
;??wLNdf-
/* Mj$dDtw
**TestMethod.java WNTm
*/ vx=I3o
package NetFox; n5_r 3{
'3uj6Wq2
~B%EvG7:n
public class TestMethod { N}\Da:_
!l'Az3'J|
F2yM2Ldx
public TestMethod() >Uvtsj#
{ ///xx/weblogic60b2_win.exe ,eRl Z3T
try{ :=04_5 z
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); RIX0AE
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); iUh_rX9A"
SiteFileFetch fileFetch = new SiteFileFetch(bean); Ms?V1
fileFetch.start(); &sL5Pt_
} z]>aWH}$
catch(Exception e){e.printStackTrace ();} a34'[R
1W;3pN
3m4?l ~
} K@VXFV
-5\aL"?4
xiU-}H'o
public static void main(String[] args) a<Pi J?
{ 9#%(%s2+
new TestMethod(); ~%^af"_
} *Rshzv[
} *MkhRLw\,
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