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)); B{|g+c%
} /CpUq;^
for(int i=0;i<nEndPos.length-1;i++) 3/IQ]8g"
{ $ tf;\R
nEndPos = nStartPos[i+1]; W-wy<<~f
} u2HkAPhD
nEndPos[nEndPos.length-1] = nFileLength; 9tZ)#@\
} 9xWC<i
} KDwz!:ye
htc& !m
$q*kD#;mh
//启动子线程 -1Y9-nn[m
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; gyH'92ck
for(int i=0;i<nStartPos.length;i++) /x.TF'Z*
{ Q,Tet&in )
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #!p=P<4M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <%eY>E
nStartPos,nEndPos,i); `B+%W
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yu"Ii-9z
fileSplitterFetch.start(); 2}j2Bhc
} ={' "ATX(U
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~XGO^P"?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); a2W}Wb+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", h"VQFqQy
nEndPos = " + nFileLength); Tks;,C
// fileSplitterFetch[nPos.length-1].start(); {9TWPB/>
"cjZ6^Hum
d7N;Fa3yL
//等待子线程结束 Du3OmXMk
//int count = 0; BqZ^I eC$
//是否结束while循环 `NA[zH,w3
boolean breakWhile = false; U -~%-gFC
GypZ!)1
8xhXS1
while(!bStop) 4mOw[}@A
{ PpMZ-f@
write_nPos(); '|^LNAx
Utility.sleep(500); K#M h
breakWhile = true; g!n1]- 1
,oe e'
-Hzn7L
for(int i=0;i<nStartPos.length;i++) ^|}C!t+
{ ZCPK{Ru QE
if(!fileSplitterFetch.bDownOver) bHlG(1uf
{ qG"|,bA
breakWhile = false; j`Lf/S!}
break; }@yvw*c
} +C7 1".i-
} 7=XQgbY/
if(breakWhile) /R#-mY
break; }yqRz6=YB
Bc}<B:q%b
`7jm
//count++; Fk D
//if(count>4) X:-X3mV9{
// siteStop(); :NU-C!eT
} 475yX-A
N>`+{
kF'^!Hp
System.err.println("文件下载结束！"); #1Mk9sxo
} EZ #UdK_
catch(Exception e){e.printStackTrace ();} *lv)9L+0
} @RotJl/>
etf ft8
La%\-o
//获得文件长度 7UHqiA`L
public long getFileSize() ?97MW a
{ Z_' %'&Y
int nFileLength = -1; q?z6|]M|u
try{ *pP"u::S
URL url = new URL(siteInfoBean.getSSiteURL()); 0kgK~\^,.O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cb&y8!ci~
httpConnection.setRequestProperty("User-Agent","NetFox"); t )Z2"_5
]SrKe-*:U
Bir}X
int responseCode=httpConnection.getResponseCode(); oSNB\G<
if(responseCode>=400) %9M; MK
{ D{o1G?A
processErrorCode(responseCode); d_J?i]AP|'
return -2; //-2 represent access is error iMx+y5O
} Y=X"YH|
mDE{s",q/
pALB[;9g
String sHeader; )xQxc.
M)Rp+uQ
)$q<"t\#P#
for(int i=1;;i++) j-gLX
{ ;TSnIC)c
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2BH>TmS
//Utility.log(in.readLine()); a2/r$Tgm
sHeader=httpConnection.getHeaderFieldKey(i); 9?D7"P+
if(sHeader!=null) s cR-|GuZ
{ X1<)B]y
if(sHeader.equals("Content-Length")) Y'fI4
{ 'G(N,vu[@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); oE#HI2X
break; P},S[GaZ
} SUD]Wl7G`r
} ?Z4&j'z<
else };9dd3X
break; %W"\
} :Tuy]]k
} gZM{]GQ
catch(IOException e){e.printStackTrace ();} (m;P,*
catch(Exception e){e.printStackTrace ();} #!#V!^ o
d\;M F
]p'Qk
Utility.log(nFileLength); N["c*=x
t{~"vD9Am
5YS`v#+
return nFileLength; 1\YX|
} v{ C]\8
qjR;c& qR
8e>;E
//保存下载信息（文件指针位置） I.x0$ac7
private void write_nPos() ~$r^Ur!E\
{ W<!q>8Xn?
try{ 74gU4T
output = new DataOutputStream(new FileOutputStream(tmpFile)); eE7Rd>
output.writeInt(nStartPos.length); |D]jdd@!a2
for(int i=0;i<nStartPos.length;i++) _?G\^^
{ DDAqgx
// output.writeLong(nPos); pMt]wyKr
output.writeLong(fileSplitterFetch.nStartPos); ([f6\Pw\ <
output.writeLong(fileSplitterFetch.nEndPos); x?CjRvT$
} .6O>P2m]a_
output.close(); Va=0R
} yWzvE:!)
catch(IOException e){e.printStackTrace ();} 83R"!w18
catch(Exception e){e.printStackTrace ();} GsDSJz
} QQ2xNNF[
o\|dm."f
Dj!J 4uD
//读取保存的下载信息（文件指针位置） DP;B*s4{U
private void read_nPos() \!cqeg*53
{ 8.-PQ
try{ aF'Ik XG d
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g?=B{V
int nCount = input.readInt(); }d.R=A9L
nStartPos = new long[nCount]; W@wT,yJ8@
nEndPos = new long[nCount]; Gw+z8^|C&}
for(int i=0;i<nStartPos.length;i++) sK?[1BI
{ ,}{E+e5jh7
nStartPos = input.readLong(); =Rb,`%
nEndPos = input.readLong(); $Fr2oSTT)
} M8juab%y
input.close(); !Z=`Wk5
} g<,v2A
catch(IOException e){e.printStackTrace ();} B|extWwu
catch(Exception e){e.printStackTrace ();} Tr@`ozp8
} ?5B}ZMW
J|xqfY@+
a*SJHBB
private void processErrorCode(int nErrorCode) {+C>^b
{ QJ"Bd`wc
System.err.println("Error Code : " + nErrorCode); &7@6Y{!/
} 2YwV}
5j]}/Aq
dDpe$N
//停止文件下载 N#,4BU
public void siteStop() ORtl~V'
{ |qI_9#M\(
bStop = true; uL-i>!"L!}
for(int i=0;i<nStartPos.length;i++) =,T~F3pK
fileSplitterFetch.splitterStop(); +!_^MBkk
;U20g:K
Q 5@~0
} W{-N,?z
} f2{4Y)
//负责部分文件的抓取 ny=CtU!z
**FileSplitterFetch.java (Mtc&+n{
*/ GuDus2#+
package NetFox; +,|-4U@dl
Rb9Z{Clq>
d9Q%GG0]
import java.io.*; 3[V|C=u0
import java.net.*; 5lU`o
!/jx4w~R
\!SC;
public class FileSplitterFetch extends Thread { ahV_4;yF
(b{ {B$O
{.!:T+'Xi\
String sURL; //File URL mDM]RAub)
long nStartPos; //File Snippet Start Position >Mvt;'c
long nEndPos; //File Snippet End Position ^2mXXAQf7^
int nThreadID; //Thread's ID gcv,]v8
boolean bDownOver = false; //Downing is over N}dJ)<(2~
boolean bStop = false; //Stop identical P%/+?(?
FileAccessI fileAccessI = null; //File Access interface "V9!srIC
zZf#E@=$|
!o.g2
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException MnX2sX|
{ z4f5@
this.sURL = sURL; U3za}3
this.nStartPos = nStart; t: [[5];E
this.nEndPos = nEnd; XD|&{/O
nThreadID = id; Q]|+Y0y}X
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .qVdo+M%F
} 2<988F
*50Ykf
Ft>ixn
public void run() R#T6Ii
{ P{}Oe *9"
while(nStartPos < nEndPos && !bStop) 9s7B1Pf
{ Pu9.Uwx
T.(SBP
xE)pj|
try{ G4RsH/
URL url = new URL(sURL); Ko%rB+d
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 94a_ W9
httpConnection.setRequestProperty("User-Agent","NetFox"); \\/X+4|o'
String sProperty = "bytes="+nStartPos+"-"; AVcZ.+?
httpConnection.setRequestProperty("RANGE",sProperty); SU#|&_wtr!
Utility.log(sProperty); { j/w3
KK] >0QAY
d9^=#ot
InputStream input = httpConnection.getInputStream(); pixI&iQ
//logResponseHead(httpConnection); +'KM~c?]
SjJUhTb
I+<`}
byte[] b = new byte[1024]; FcWu#}.p}
int nRead; B[$SA-ZHi
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &1?Q]ZRp
{ qh&K{r*T
nStartPos += fileAccessI.write(b,0,nRead); 6Edqg
//if(nThreadID == 1) )b-G2< kb
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zh4o<f:-
} snK9']WXo
H~$|y9>qI
|j!D _j#U
Utility.log("Thread " + nThreadID + " is over!"); 4B> l|%
bDownOver = true; Qy$QOtrv
//nPos = fileAccessI.write (b,0,nRead); PAc~p8S
} p5[uVRZ
catch(Exception e){e.printStackTrace ();} -!}1{
} 1u`Z?S(
} %idnm
@=,J6
$"UAJ-
//打印回应的头信息 H{}6`;W
public void logResponseHead(HttpURLConnection con) ]':C~-RV{
{ (%r:PcGMEV
for(int i=1;;i++) AVJF[t,
{ #/ 4Wcz<
String header=con.getHeaderFieldKey(i); -Kc-eU-&q
if(header!=null) |/(5GX,X
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r;'!qwr
Utility.log(header+" : "+con.getHeaderField(header)); s=d?}.E$
else j=gbUXv/
break; EP8LJzd"
} mb/3 #)
} O^<6`ku
P9'5=e@jB
<T}#>xHs3
public void splitterStop() O:U@m@7
{ vx4& ;2
bStop = true; m&%N4Q~X>
} m:^@AR1%d
Kr#=u~~M
T8\,2UWsj2
} %sq=lW5R{b
K)v(Z"
'0=U+Egp
/* 4 '+)9&g
**FileAccess.java ~W#f,mf
*//文件访问(定位，写) $K iMu
package NetFox; 7]^Cg;EtM:
import java.io.*; *\`C!r
jsG9{/Ov3
BNByaC
public class FileAccessI implements Serializable{ F+6ZD5/
p!691LI
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ky'^AN]
RandomAccessFile oSavedFile; u)V*o
long nPos; PQ[TTLG\&
K4rr.f6
t.zSJ|T_&O
public FileAccessI() throws IOException z6!X+`&
{ _I!Xr!!)a0
this("",0); &p%,+|
} z=xHk|+'
h}oQr0"c
d}G?iX;c}
public FileAccessI(String sName,long nPos) throws IOException z~BB|-kp1
{ w Vof_'F1
oSavedFile = new RandomAccessFile(sName,"rw"); [X I5Bu ~
this.nPos = nPos; Cse0!7_T
oSavedFile.seek(nPos); _E%[D(
} mSzwx/3"
p"JSYF 9]
EW!$D
public synchronized int write(byte[] b,int nStart,int nLen) AVJk
{ tL5Xfd?u
int n = -1; GGBe/X
try{ a~%ej.)l
oSavedFile.write(b,nStart,nLen); _c&*'IY[V
n = nLen; VgdkCdWRm_
} Q(sbClp"
catch(IOException e) S ~_%
{ 5A)w.i&V
e.printStackTrace (); GBQb({
} `%=Jsi0.Nq
8iCIs=06
sH]AB=_
return n; *HC8kD a%$
} Y1~SGg7(@
=j{jylC
`~}7k)F(
} X=hgLK^3<,
lVFX@I=pI
*"5a5.`%,
/* `%Ghtm*
**SiteInfoBean.java y"hM6JI
*/ MT5A%|He
package NetFox; d{he
EH:1Z*|Z{\
q^cFD
public class SiteInfoBean { <Z;7=k
&SM$oy#?
^M9oTNk2
private String sSiteURL; //Site's URL P=@lkF!\#
private String sFilePath; //Saved File's Path GKSy|z
private String sFileName; //Saved File's Name Q.XsY.{
private int nSplitter; //Count of Splited Downloading File ,dp?'_q{
pxbNeqK@p
vP4Ij
public SiteInfoBean() s,k1KTXg<B
{//nSplitter的缺省值为5 IX(yajc[~M
//default value of nSplitter is 5 =, 0a3D6b
this("","","",5); 9e&#;6l
} GW#kaqC1
:2My|3H\
z]YhQIU4n8
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 85fDuJ9$Z"
{ AN>`M?EQ
sSiteURL= sURL; B#MW`7c
sFilePath = sPath; =tNiIU
sFileName = sName; Tc(R-Wi
this.nSplitter = nSpiltter; {XXNl)%
;40m goN
<f6PULm
} J){\h-4
-IS9uaT5
}ELCnN
public String getSSiteURL() de6dLT>m
{ nnNg^<[k3
return sSiteURL; t4*A+"~j
} %MJ7u}
0q>lW &J
;5k|gW
public void setSSiteURL(String value) C6M/$_l&a
{ `.W;ptZ6
sSiteURL = value; DxgT]F%
} gk1S"H
orHD3T%&
WS/+Yl
public String getSFilePath() %`1vIr(7
{ ewG21 q$
return sFilePath; c.Y8CD.tqL
} ;8T=uCi
~BZV:Es
;QQ7vo
public void setSFilePath(String value) 5#)<rK
{ HdUW(FZ
sFilePath = value; KL mB
} BznA)EK?@
grdyiBSVn
_ICDtG^
public String getSFileName() b=UMoWS
{ 4.B*B3
return sFileName; vx@p;1RU`
} l&Ghs@>Kl
dO;vcgvb
xg^^@o
public void setSFileName(String value) ('-}"3
{ X9A[
sFileName = value; |a$w;s>\
} Z{4aGp*
pf@}4PN}
*.c9$`s
public int getNSplitter() (I ds<n"
{ K=?F3tX^
return nSplitter; ]C6[`WF
} idS RWa
zZc@;S#
W7=_u+0d
public void setNSplitter(int nCount) \y`3LhY
{ -xu.=n@,
nSplitter = nCount; R(83E B~_
} <1+6O[>{
} ~:<@`
!b->u_
7 eQoc2X2
/* j4xr1y3^
**Utility.java 'xZPIj+
*/ K}<!{/fi)
package NetFox; %)Uvf`Xhh4
h_chZB'
E D^rWE_
public class Utility { x<j"DS}S)D
?U/Wio$@
`6N-MsP
public Utility() Y+u-J4bj
{ u%1k
8C,utjy
ObyuhAR
} ho]!G498
@Du}
//线程睡眠 Y`7#[g
public static void sleep(int nSecond) #!Cter2
{ #G+
try{ -Bo~"q
Thread.sleep(nSecond); TflS@Z7C
} 9g &Ch9-/
catch(Exception e) BZ;}ROmqk
{ Ym.l@(
e.printStackTrace (); B+e_Y\Bu
} tkN3BQ
} T$^>Fiz{Se
$#7J\=GZ+
//日志 4%fN\f
public static void log(String sMsg) q= yZx)
{ 3']:1B
System.err.println(sMsg); +8)]m<
} TjUZv1(L
fAMD2C
,B~lwF9
public static void log(int sMsg) rbK#a)7
{ 45)ogg2
System.err.println(sMsg); Ku/H=
} : \:~y9X0
} Wz-3?EQ
s"=F^#
!0OD(XT
/* [CDXCV-z
**TestMethod.java hX8gV~E=y
*/ 1t[;`iZ
package NetFox; ` -[Bo
C^,4`OI
&V#zkW
public class TestMethod { {yHB2=nI
gR;8ht(pd(
uspkn1-
public TestMethod() ;c X^8;F0
{ ///xx/weblogic60b2_win.exe [-E{}FL|
try{ <E[HlL
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -eR!qy:.]5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); DrCWvpudd
SiteFileFetch fileFetch = new SiteFileFetch(bean); :otY;n-
fileFetch.start(); [W9e>Nsp0
} H-_^TB
catch(Exception e){e.printStackTrace ();} D/S>w(=
M9Nk=s! 3
qIDWl{b<
} hY.e[+
jSie&V@px
/o|PA:6J
public static void main(String[] args) xTJSr2f
{ #a(%(k S
new TestMethod(); pkXfsi-Nu
} #hgmUa
} =!?[]>Dh
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