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)); a6 1!j>Kx
} 9C0#K\
for(int i=0;i<nEndPos.length-1;i++) iq[IZdza
{ 1ANb=X|hig
nEndPos = nStartPos[i+1]; vm'ZA7f6
} lW|v_oP9
nEndPos[nEndPos.length-1] = nFileLength; JodD6;P
} ic"8'Rwb
} Vzo<ma^
n.z,-H17
?r@^9
//启动子线程 QWEE%}\3}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; @BF1X.4-+
for(int i=0;i<nStartPos.length;i++) wy0?*)~
{ yMTO5~U{
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M.r7^9P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }a.j~>rq
nStartPos,nEndPos,i); !?/:p.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Pg{1'-
fileSplitterFetch.start(); 0H]{,mVs
} KIag(!&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,&qC R sw
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4+s6cQ]S`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", k)|.<
nEndPos = " + nFileLength); %yu =,J j
// fileSplitterFetch[nPos.length-1].start(); "aCAA#$J
x3Y)l1gh
kS:#|yY8%
//等待子线程结束 _lFw1pa#\
//int count = 0; *8/Xh)B;
//是否结束while循环 fe,6YXUf
boolean breakWhile = false; Zd-6_,r
!hhL",
\r[u>7I
while(!bStop) AyOibnoZ2E
{ V?1 $H
write_nPos(); 5UO+c(T
Utility.sleep(500); -4& i t:
breakWhile = true; C5,fX-2Q
$R1I(sJ
G9 O6Fi
for(int i=0;i<nStartPos.length;i++) . yg#
{ tmooS7\a
if(!fileSplitterFetch.bDownOver) ACdPF_Y]
{ ABX%oZ7[|o
breakWhile = false; A>1$?A8Q
break; .t5.(0Xk[A
} 4^F%bXJ)
} 9ziFjP+1
if(breakWhile) =I@t%Y
break; (^m] 7l
_y_}/
q!eE~O;A
//count++; jk03 Hd
//if(count>4) Aj4 a-vd.
// siteStop(); {;c'@U
} At4\D+J{Vs
<f>w"r
>8>!wi9U
System.err.println("文件下载结束！"); )Y7H@e\1
} Og/aTR<;=
catch(Exception e){e.printStackTrace ();} bOFzq>k_
} ` 3qf}=Z`
30!DraW8
yx :^*/
//获得文件长度 8(L$a1#5W
public long getFileSize() }kqh[`:
{ ,X4+i8Yc
int nFileLength = -1; Mw/9DrE7/
try{ o@e/P;E
URL url = new URL(siteInfoBean.getSSiteURL()); (Xh<F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); sFTAE1|
httpConnection.setRequestProperty("User-Agent","NetFox"); WiS3W;
7~e,"^>T
4,I,f>V
int responseCode=httpConnection.getResponseCode(); XB7Aa)
if(responseCode>=400) nF<K84
{ ES~b f
processErrorCode(responseCode); pCs3-&rI3
return -2; //-2 represent access is error mgAjD.
} im2mA8OH
K ze?@*
'[ t.
String sHeader; _;j1g%
MA`nFkVK
>GGM76vB=,
for(int i=1;;i++) R^l0Bu]X
{ Z7a@$n3h
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6]brL.eGj
//Utility.log(in.readLine()); EZ)b E9
sHeader=httpConnection.getHeaderFieldKey(i); &n6{wtBP
if(sHeader!=null) q]?qeF[
{ tO M$'0u
if(sHeader.equals("Content-Length")) MzIDeZ
{ 4z0gyCAC A
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4&mY-N7A
break; M\R+:O&
} dk|LC-]`A
} |OH*c3~r
else GW,EyOE+~
break; /mkT7,]
} Lh[0B.g<
} rl|'.~mc
catch(IOException e){e.printStackTrace ();} uy{O
catch(Exception e){e.printStackTrace ();} & FhJ%JK
CvU$Fsb
q\EYsN</;
Utility.log(nFileLength); 4z<c8 E8
Bb/if:XS
u7< +)6-
return nFileLength; ;'S,JGpvT
} duG!QS:
`K{}
I3Vu/&8f|
//保存下载信息（文件指针位置） ^*ZaqMA
private void write_nPos() 32ki ?\P
{ t2dsYU/
try{ 9JA@m
output = new DataOutputStream(new FileOutputStream(tmpFile)); OJ&'Z}LB
output.writeInt(nStartPos.length); l U/Xi
for(int i=0;i<nStartPos.length;i++) ]Y[N=G
{ 2IB{FO/
// output.writeLong(nPos); (<Cq_Kw
output.writeLong(fileSplitterFetch.nStartPos); j\ y!
output.writeLong(fileSplitterFetch.nEndPos); vb>F)X?b_
} +=($mcw#[
output.close(); r2RJb6
} @[r[l#4yUi
catch(IOException e){e.printStackTrace ();} eK7A8\;e
catch(Exception e){e.printStackTrace ();} c(Dp`f,
} v'hc-Q9+>
;%n'k
u"0{) ,
//读取保存的下载信息（文件指针位置） 1M`E.Ztw*
private void read_nPos() ,WyEwc]
{ x1 |/
try{ 3yx[*'e$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); rj=as>6B
int nCount = input.readInt(); {!2K-7;
nStartPos = new long[nCount]; +R*DE5dz
nEndPos = new long[nCount]; 7NvKpinQ
for(int i=0;i<nStartPos.length;i++) $FPq8$V
{ 2K:A4)jZ
nStartPos = input.readLong(); }d.X2?
nEndPos = input.readLong(); &PC6C<<f
} =;Q/bD->
input.close(); ](JrEg$K
} T,!EL+o4
catch(IOException e){e.printStackTrace ();} R'gd/.[e
catch(Exception e){e.printStackTrace ();} FAM{p=t]HT
} F3bTFFt
B{/og*xd*1
UwUHB~<oE
private void processErrorCode(int nErrorCode) _$UJ'W})/
{ X.<3/
System.err.println("Error Code : " + nErrorCode); Z^'~iU-?
} h3`}{ w
ST{Vi';}
UNDl&C2vz
//停止文件下载 1m5l((d
public void siteStop() Rw'}>?k]
{ :)lS9<Y}
bStop = true; N}#Rw2Vl
for(int i=0;i<nStartPos.length;i++) 1'f_C<.0
fileSplitterFetch.splitterStop(); )%^l+w+&
$W7}Igx#
]$2 yV&V&
} [!)HWgx
} \ ITd\)F%N
//负责部分文件的抓取 Cf(WO-F^
**FileSplitterFetch.java I0x)d`
*/ M-t9M~
package NetFox; g>t1rZ
Pm%xX~H
>N#Nz 0|(
import java.io.*; 3zB'AG3b
import java.net.*; 4w+AOWjd
pFH.beY
U5C]zswL
public class FileSplitterFetch extends Thread { Dn)yBA%
E_~e/y"-
]EHsRd
String sURL; //File URL (#y2RF8j
long nStartPos; //File Snippet Start Position :!_l@=l
long nEndPos; //File Snippet End Position xT 06*wQ
int nThreadID; //Thread's ID [~8U],?1
boolean bDownOver = false; //Downing is over P%:?"t+J`;
boolean bStop = false; //Stop identical ;j9%D`u<
FileAccessI fileAccessI = null; //File Access interface ND1hZ3(^
f+9eB
:#g.%&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException I3 "6"
{ :,l16{^
this.sURL = sURL; E2M<I;:EA
this.nStartPos = nStart; T'}kCnp
this.nEndPos = nEnd; d0B`5#4
nThreadID = id; {> ,M
fileAccessI = new FileAccessI(sName,nStartPos);//定位 IM1&g7Qs2
} Lk|`\I T
F'|K>!H
-Kg.w*\H7/
public void run() ?lkB{-%rQ
{ el2Wk@*
while(nStartPos < nEndPos && !bStop) `V9bd}M%~;
{ w<H2#d>5!@
8XYxyOl
dDA8IW![S
try{ ;"cQ)=s9Y
URL url = new URL(sURL); )Wle CS_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v' t'{g%
httpConnection.setRequestProperty("User-Agent","NetFox"); eGT&&Y
String sProperty = "bytes="+nStartPos+"-"; PESvx>:
httpConnection.setRequestProperty("RANGE",sProperty); lD0a<L3
Utility.log(sProperty); 1qR$ Yr\
C!:Lk,Z
YZ<zlU
InputStream input = httpConnection.getInputStream(); gHc1_G]
//logResponseHead(httpConnection); M@KQOAzt
]2l}[ w71|
,y'6vW`%g9
byte[] b = new byte[1024]; wlP3 XF?
int nRead; j_d}?jh
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) O[= L#wi
{ tm/>H
nStartPos += fileAccessI.write(b,0,nRead); @?e~l:g})g
//if(nThreadID == 1) L+G0/G}O\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?{aC-3VAT
} :[+8(~| za
Ms+ekY)
|=ph&9
Utility.log("Thread " + nThreadID + " is over!"); Z$INmo6
bDownOver = true; TrzAgNt
//nPos = fileAccessI.write (b,0,nRead); ilQ}{p6I
} eCR^$z=c
catch(Exception e){e.printStackTrace ();} `Y.~eE
} [-[59H[6)
} %\-E R!b
pYzop4
2~\SUGW-
//打印回应的头信息 LZ_0=Xx%
public void logResponseHead(HttpURLConnection con) qE2VUEv5Y
{ baD063P;
for(int i=1;;i++) 1OExa<Zq
{ N$e mS
String header=con.getHeaderFieldKey(i); V*PL_|Q5
if(header!=null) 5,p;b
//responseHeaders.put(header,httpConnection.getHeaderField(header)); SF-E>s!XL
Utility.log(header+" : "+con.getHeaderField(header)); "`cN k26JZ
else ,vmn{gz
break; ,x1OQ jtY
} .-iW T4Dn
} pt"9zkPj
AB\Ya4O"9
a(6h`GHo
public void splitterStop() &-qQF`7
{ (_4DZMf
bStop = true; pl3ap(/
} >i*,6Psl[Z
[m{sl(Q
`XH0S`B
} ;PC!
OFtf)cGE
J)n_u),
/* <-?C\c~G@
**FileAccess.java v[|W\y@H/3
*//文件访问(定位，写) NW5OLa")J<
package NetFox; Jn=;gtD-*
import java.io.*; nl 'MWP
q 0F6MAXj
,k~' S~w.
public class FileAccessI implements Serializable{ WtZI1`\qe
uU3A,-{-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :p}8#rb
RandomAccessFile oSavedFile; 9\hI:rI
long nPos; }~+,x#
':;k<(<-
1Zn8CmE V
public FileAccessI() throws IOException f0SrPc v
{ ;x\oY6:
this("",0); E>]K#H
} WqF,\y%W*
t}_ #N'`
tjFX(;^[
public FileAccessI(String sName,long nPos) throws IOException mTI`^e
{ lvWwr!w
oSavedFile = new RandomAccessFile(sName,"rw"); \fTQNF
this.nPos = nPos; ISNL='%
oSavedFile.seek(nPos); %\<b{x# G
} ujxr/8mjV
0pMN@Cz6
_|GbU1Hz
public synchronized int write(byte[] b,int nStart,int nLen) %a~/q0o>
{ -sQ[f18
int n = -1; U)bv,{-q
try{ cp(qaa
oSavedFile.write(b,nStart,nLen); [o#% Eg;
n = nLen; DO80HS3ZD
} KCTX2eNN&h
catch(IOException e) (|^m9v0:
{ h[]9F.[
e.printStackTrace (); VGQ~~U7}@
} :Mu*E5
QnVr)4"
7tcadXk0
return n; }aRib{L
} 4uIYX
g&FTX>wX
2DCQ5XewYe
} r+FEgSDa]
N;|^C{uz
kCTf>sJe
/* b4_0XmL
**SiteInfoBean.java Kn~Rck| ]
*/ Ax=HDW}
package NetFox; k3#'g'>yh
ls@]%pz.1d
p +i1sY
public class SiteInfoBean { [7v|bd
_!',%+
sE"s!s/
private String sSiteURL; //Site's URL Z[. M>|
private String sFilePath; //Saved File's Path 6$r\p2pi0
private String sFileName; //Saved File's Name }sXTZX
private int nSplitter; //Count of Splited Downloading File dDPQDIx
^AP8T8v
WBE>0L
public SiteInfoBean() 3gi)QCsk
{//nSplitter的缺省值为5 ~gfR1SE
//default value of nSplitter is 5 x z_sejKB
this("","","",5); y"JR kJ
} 3 ~v 17
[r/zBF-.
WkTJ M
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (9'^T.J
{ Z4] n<~o
sSiteURL= sURL; 2zTi/&K&
sFilePath = sPath; @[n#-!i
sFileName = sName; %T/@/,7h
this.nSplitter = nSpiltter; ?"d$SK"6Z
8 t5kou]h
s\-,RQ1
} jo`ZuN{
s*izhjjX
iEvQ4S6tD
public String getSSiteURL() 5f-b>=02
{ cSb;a\el$
return sSiteURL; $GJT
} 4yl{:!la
{OU|'
]\78(_o.zz
public void setSSiteURL(String value) ~G!JqdKJ0
{ Ww7Ya]b.k
sSiteURL = value; A lU^,X
} =kd$??F
%**f`L%jN
H9cPtP~a)
public String getSFilePath() cl4E6\?z
{ $]2)r[eA)
return sFilePath; ";K w?
} CXlbtpK2k
*pKTJP
U.7fMc#
public void setSFilePath(String value) %M(RV_R+6
{ /A=w`[<
sFilePath = value; aB]0?C y9(
} %Y^J''
/)P}[Q4
$]v}X},,
public String getSFileName() )Z}AhX
{ rpR${%jc
return sFileName; =*mT{q@
} )g0fN+Mb
R@vcS=m7
UiFH*HT
public void setSFileName(String value) /R)wM#&
{ +&EXTZ@o
sFileName = value; )#=J<OpG
} #~u0R>=
Gz[yD ~6a
)-C3z
public int getNSplitter() .Eao|;
{ CD|[PkjW
return nSplitter; j)A#}4jd
} tXD$HeBB?
4=zs&
JAPr[O&
public void setNSplitter(int nCount) :{lwz#9V
{ 8%?y)K^ D
nSplitter = nCount; 1yy?1&88S
} kB\{1;
} jc}G+|`
K=g</@L6R
}f}.>B0#
/* bDI%}k9#
**Utility.java PnlI {d
*/ <n"BPXF~
package NetFox; 8[^'PIz
M6Fo.eeK3
eI #Gx_mg
public class Utility { 6b|?@
gv#\}/->4
1H)mJVIKkB
public Utility() NkE0S`Xf
{ L*nK> +
cNs'GfD}
U)S=JT~h
} U, 6iT
" qI99e
//线程睡眠 W:w~ M'o
public static void sleep(int nSecond) zM0NRERi
{ >ZA=9v
try{ x-^6U
Thread.sleep(nSecond); 8xpplo8
} WzMYRKZ
catch(Exception e) p7?
{ %x)bZ=An
e.printStackTrace (); xo:kT)
} +^)v"@,VP
} jvT'N@
J 3!~e+wn
//日志 a"8[,A3
public static void log(String sMsg) 9g92eKS
{ ZedFhm
System.err.println(sMsg); <v"o+
} rS8a/d~;0
DE?v'7cmA
?RRO
public static void log(int sMsg) c:R?da
{ V"FQVtTx7
System.err.println(sMsg); '<Z[e`/
} (IJNBJb
} Cs $5Of(
]rcF/uQJ<n
L`NIYH<^
/* ^?z%f_ri
**TestMethod.java <@<rU:o=V
*/ *kr/,_K
package NetFox; Qm%F]nyy
f|RmAP;X,
u\R?(G&
public class TestMethod { .UyE|t4
5*0zI\
tDByOml8Ix
public TestMethod() xn8KOwX%
{ ///xx/weblogic60b2_win.exe !iXRt")
try{ Z\0Rw>#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); E&[5b4D@<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8\"<t/_ W
SiteFileFetch fileFetch = new SiteFileFetch(bean); ez4!5&TzRm
fileFetch.start(); Uj@th
} ">uN={Iy
catch(Exception e){e.printStackTrace ();} {@Wv@H+4
m0HK1'
'uPAG;)m
} "gJ?LojB<
Z9{~t
]5Cr$%H=
public static void main(String[] args) Ik G&
{ !\4x{Wa]
new TestMethod(); Mk!Fy]3
} T^bAO-d#
} OvfluFu7
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