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)); *q/oS8vavd
} 5Zdxn>
for(int i=0;i<nEndPos.length-1;i++) -+#g.1UL/
{ 7<?~A6
nEndPos = nStartPos[i+1]; Z-BPC|e
} ;q6FdS
nEndPos[nEndPos.length-1] = nFileLength; B\z4o\am%
} #H1ng<QV
} E%E3h1Ua
g,seqh%
5 LZ+~!2+
//启动子线程 '5vgpmn
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; std4Nyp
for(int i=0;i<nStartPos.length;i++) sG~5O\,E
{ h0)Wy>B=,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Gj}P6V_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), BHW8zY=F
nStartPos,nEndPos,i); XCTee
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s]p3dB#
fileSplitterFetch.start(); B{0m0-l
} RO1xcCp
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (!0=~x|Z[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5$ra4+k0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", e2?7>?
nEndPos = " + nFileLength); !SFF 79$c
// fileSplitterFetch[nPos.length-1].start(); <Hq|<^_K
X(;,-7Jw
T;u>]"S
//等待子线程结束 BEv>?T 0
//int count = 0; 8yDu(.Q
//是否结束while循环 !Xbr7:UPN1
boolean breakWhile = false; C$1}c[
k^IC"pUc
XdDy0e4{%<
while(!bStop) .CL\``
{ fem>WPvG
write_nPos(); ~Z'3(n*9
Utility.sleep(500); |<n+6
breakWhile = true; K8l|qe
U_UX *
.d;XLS~
for(int i=0;i<nStartPos.length;i++) \HzI*|*A
{ 'b* yYX<
if(!fileSplitterFetch.bDownOver) <R.5Ma
{ N:y3tpG
breakWhile = false; m-Uq6_e
break; LI&+5`
} 3PEv.hGx
} ZMHb
if(breakWhile) cIO7RD$8
break; [7~ !M*o9
JRm:hf'
hK+Iow-
//count++; P>dMET
//if(count>4) 8W]6/st?]
// siteStop(); pOCLyM9c
} C#<:x!
^fLePsmd
]Xur/C2A
System.err.println("文件下载结束！"); R18jju>Zr
} ov=[g l
catch(Exception e){e.printStackTrace ();} K>h=
} 8gv\`
aIv>X@U}
T'cahkSw'O
//获得文件长度 T #&9|
public long getFileSize() L44/eyrp
{ XF{ g~M
int nFileLength = -1; Xz'pZ*Hr$v
try{ 1Z +3=$P
URL url = new URL(siteInfoBean.getSSiteURL()); [=Y@Ul
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1}C|Javkn
httpConnection.setRequestProperty("User-Agent","NetFox"); k;w1y(
`4RraJj>0~
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int responseCode=httpConnection.getResponseCode(); IRemF@
if(responseCode>=400) <|NP!eMsw8
{ b<de)MG
processErrorCode(responseCode); ?q(7avS9
return -2; //-2 represent access is error Uj)~>V'
} ,c@^u6a
XHgwK@GU
y#:_K(A" k
String sHeader; :h tOz.
P"J(O<(1-:
4|uh&4"*@W
for(int i=1;;i++) ysV0Ed
{ k[]B P4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (bxSN@hp2
//Utility.log(in.readLine()); L\Uf+d:&}G
sHeader=httpConnection.getHeaderFieldKey(i); =h?WT*
if(sHeader!=null) y]B?{m``6
{ [2UjY^\;T
if(sHeader.equals("Content-Length")) )z/+!y
{ ]A:n]mL
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); C`z[25o
break; ')w:`8Tl
} !>g_9'n'
} ty|E[Ez1
else Ll%CeP
break; 5Xu2MY=
} %nQii?1`i
} c(.2D
catch(IOException e){e.printStackTrace ();} Kv'2^B
catch(Exception e){e.printStackTrace ();} \0iF <0oy
VLuhURI)
gnW`|-:\
Utility.log(nFileLength); <=A1d\
D9M<>Xz)
#5xK&qA
return nFileLength; Y]aVa2!Wb
} MzRwsf
D.zEE-cGyb
Vv4w?K
//保存下载信息（文件指针位置） ~ztsR;iL
private void write_nPos() =B g
{ -t_t3aU|
try{ bT<if@h-
output = new DataOutputStream(new FileOutputStream(tmpFile)); n}MW# :eJe
output.writeInt(nStartPos.length); *Ppb;
for(int i=0;i<nStartPos.length;i++) eXY*l>B
{ =m.Lw
// output.writeLong(nPos); v/{LC4BF
output.writeLong(fileSplitterFetch.nStartPos); luYkC@I@a
output.writeLong(fileSplitterFetch.nEndPos); NGIbUH1[
} 0Ym+10g
output.close(); `0Y`]kSY+
} }{Ab:+aNd
catch(IOException e){e.printStackTrace ();} #Hl0>"k ,
catch(Exception e){e.printStackTrace ();} =&RpW7]
} DT`TA#O
5qzFH,
f 4CS
//读取保存的下载信息（文件指针位置） 1'or[Os3=
private void read_nPos() MaDdiyeC
{ 68 %= V>V
try{ XdX1GH*C
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); fvn`$
int nCount = input.readInt(); 0|kkwZVPn
nStartPos = new long[nCount]; E|OB9BOS
nEndPos = new long[nCount]; =e2|:Ba!
for(int i=0;i<nStartPos.length;i++) sdF;H[
{ @j*K|+X"
nStartPos = input.readLong(); (3Hz=k_
nEndPos = input.readLong(); u`I&&
} ;i*<HNQ
input.close(); | +osEHC
} p|!5G&O,
catch(IOException e){e.printStackTrace ();} U5N/'p%)<
catch(Exception e){e.printStackTrace ();} oc+TsVt
} ?.tnaE
ru#,pJ=O(
p4QQ5O$;
private void processErrorCode(int nErrorCode) qdkhfm2(K
{ |[apLQ6
System.err.println("Error Code : " + nErrorCode); h"Qp e'D}
} eT33&:n4
)Qe<XJH!
77D>;90>?
//停止文件下载 f]Jn\7j4
public void siteStop() H9}z0VI
{ G`H4#@]
bStop = true; ] TY$
for(int i=0;i<nStartPos.length;i++) dm8N;r/w
fileSplitterFetch.splitterStop(); to-DXT.
lrqu%:q
"Sm'TZx
} xNlxi
} {nvF>
//负责部分文件的抓取 4&b*|"Iw
**FileSplitterFetch.java kr ,&aP<,
*/ =-wF Brw
package NetFox; qWz%sT?C3L
E,u/^V9x
H_w&_h&
import java.io.*; 6Ih8~Hu
import java.net.*; g{|F<2rd[m
mX8k4$z
.[mI9dc
public class FileSplitterFetch extends Thread { ?8AV-rRX
r<< ]41
M_ *KA
String sURL; //File URL S7i,oP7
long nStartPos; //File Snippet Start Position @">^2
long nEndPos; //File Snippet End Position UAleGR`,
int nThreadID; //Thread's ID &CP]+ at
boolean bDownOver = false; //Downing is over zciL'9
boolean bStop = false; //Stop identical :wWPEhK
FileAccessI fileAccessI = null; //File Access interface lICpfcc(+
\!`k:lusa
=CBY_
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException MZJ@qIg[Y
{ okwkMd-yW
this.sURL = sURL; vndD#/lXq
this.nStartPos = nStart; CMu/n]?c
this.nEndPos = nEnd; ckDWY<@v
nThreadID = id; b&wyp@k
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8v{0=9,Z
} 'PO+P~|oa&
M N-j$-y}
iO$Z?Dyg9
public void run() 95cIdF 6m
{ V46=48K.
while(nStartPos < nEndPos && !bStop) [f._w~
{ 3[_zz;Y*d
1u`{yl*+?
9NXL8QmC8
try{ oU|yBs1
URL url = new URL(sURL); eMT}"u8$A
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JSp V2c5Q
httpConnection.setRequestProperty("User-Agent","NetFox"); 4Nylc.2mi
String sProperty = "bytes="+nStartPos+"-"; q>X30g
httpConnection.setRequestProperty("RANGE",sProperty); JWB3;,S
Utility.log(sProperty); Y8i'=Po%,
n1Ic[cM}
#_(t46
InputStream input = httpConnection.getInputStream(); C!,|Wi2&
//logResponseHead(httpConnection); le7!:4/8
!+R_Z#gB
T:<mme3v
byte[] b = new byte[1024]; "UM*(&
int nRead; Z'Uc}M'U
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %"yy8~|
{ i!yu%>:M
nStartPos += fileAccessI.write(b,0,nRead); :"Gx
//if(nThreadID == 1) ta;q{3fe
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GkU]>8E'"
} :o37 V!
itU P%
y [jck:
Utility.log("Thread " + nThreadID + " is over!"); Aq]*$s2\G
bDownOver = true; @Z+(J:Grm5
//nPos = fileAccessI.write (b,0,nRead); [D$%LRX
} $!LL
catch(Exception e){e.printStackTrace ();} Uo]x6j<
} F/ si =%
} 5w9oMM{
PI-o)U$Ehv
T[(4z@d`5
//打印回应的头信息 :qAF}|6
public void logResponseHead(HttpURLConnection con) |'+ [ '
{ sjW;Nsp
for(int i=1;;i++) sUe<21:
{ Jf</83RZ
String header=con.getHeaderFieldKey(i); j&y>?Y&Sb
if(header!=null) }L|cg2y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 7g%.:H=
Utility.log(header+" : "+con.getHeaderField(header)); ^U;r>[T9h
else f53WDI6
break; eVvDis
} h0c&}kM
} fU^6h`t
a +lTAe
@%[ dh@oY
public void splitterStop() 0}4FwcCr\
{ 8GKqPS+
bStop = true; 2EAY`}Rl6.
} K0 6 E:
UmNh0nS
z~0f[As.
} <c!I\y
u^X,ASkQ
a? <Ar#)j
/* \X]
**FileAccess.java yv+DM`0
*//文件访问(定位，写) o|njgmF;\
package NetFox; |+h8g@;Z
import java.io.*; _ry7[/)
R64/m9
O_^X:0}
public class FileAccessI implements Serializable{ "raC?H
au?5^u\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 p6*|)}T_%
RandomAccessFile oSavedFile; dk@j!-q^
long nPos; .!2Ac
\0bZ1"
mA" 82"
public FileAccessI() throws IOException ) mG
{ Xxmvg.Nl
this("",0); OE8H |?%
} ^(.utO
k<.VR"I p
@'lO~i
public FileAccessI(String sName,long nPos) throws IOException no UXRQ
{ 8 aC]" C
oSavedFile = new RandomAccessFile(sName,"rw"); qJ5gdID1_
this.nPos = nPos; *<IQ+oat,a
oSavedFile.seek(nPos); U66}nN9
} Y)KO*40c
D Kng.P
B`;DAsmT
public synchronized int write(byte[] b,int nStart,int nLen) _ ATIV
{ ?5Ub&{
int n = -1; #fkOm Y7X
try{ ~'3hK4
oSavedFile.write(b,nStart,nLen); !1{kG%B=
n = nLen; ZNjqH[
} f<K7m
catch(IOException e) j87IxB?o
{ 1v"r8=Wt
e.printStackTrace (); M\w%c5
} R3!3TJ
&-B&s.,kj
Q!(qL[o
return n; (.J8Q
} m=e#1Hs
z<Y >phc
>^V3Z{;
} +f]\>{o4
lBcRt)_O7
qcdENIy0b
/* ]>'yt #]
**SiteInfoBean.java 3!<} -sW4
*/ B_uAa5'
package NetFox; EC0M0qQ
u4,b%h.
@"$rR+r'
public class SiteInfoBean { ^{(i;IVG
5^GFN*poig
VQ]MJjvb
private String sSiteURL; //Site's URL $ix*xm. 4m
private String sFilePath; //Saved File's Path DUOSL
private String sFileName; //Saved File's Name ,`nl";Zc
private int nSplitter; //Count of Splited Downloading File qW(_0<E
$KGpcl
mzoNXf:x
public SiteInfoBean() }N}\<RG
{//nSplitter的缺省值为5 8QaF(?
//default value of nSplitter is 5 J"W+9sI0
this("","","",5); J`@#yHL
} Vo-]&u&cr
eHy.<VX
i<]Y0_?s
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #&jr9RB
{ 4t;m^Iv
sSiteURL= sURL; d;c<" +
sFilePath = sPath; kn1+lF@
sFileName = sName; x[i Et%_
this.nSplitter = nSpiltter; gbc])`aJ>
4 fxD$%9
?=lnYDj
} ;N/=)m
}^/;8cfLY
-a(\(^NW
public String getSSiteURL() Z<t(h=?
{ fqgm`4>
return sSiteURL; 6opubI<
} <0hJo=6a8
-$J%.fdPs
;n-IpR#|
public void setSSiteURL(String value) /^>yDGT,0
{ N;BS;W5I
sSiteURL = value; J@I-tS
} mK2M1r
w}jH,Ew
H%\\-Z$#
public String getSFilePath() I$7TnMug
{ 6qgII~F'
return sFilePath; ^-'t`mRl]d
} ->S6S_H/+&
EjYCOb-
9+sOSz~ P
public void setSFilePath(String value) k-M-=VvA
{ b[I;6HW
sFilePath = value; $*u{i4b
} <Gr775"
}nW)+
,UD,)ZPf[
public String getSFileName() ecI[lB
{ E*t0ia8
return sFileName; =>7\s}QZ
} bCmhlSNi
aF'9&A;q
@$(/6]4p
public void setSFileName(String value) +yYv"J
{ 8'kA",P
sFileName = value; B?xu!B,
} ZoiCdXvTN
9g*MBe:
"w\Iz]
public int getNSplitter() W]v[Xm$q
{ Je6=N3)
return nSplitter; pSq3\#Twr
} )n[ oP%
GAlAFsB
bh8IF,@a
public void setNSplitter(int nCount) 32flOi:
{ Odo"S;)
nSplitter = nCount; -;?5<>zZ
} w]{NaNIeq1
} FB0y
B0:[3@P7
2Q,8@2w;
/* <p'~$vK
**Utility.java wghz[qe
*/ 3psCV=/z
package NetFox; &!3=eVg
FH'jP`
N>fC"
public class Utility { xwH+Q7O&l
SRN:!-
35;)O -
public Utility() BHwQB2t gc
{ cs?@Ri=g
jG3}V3|.
S"iQQV{)Z
} vYD>m~Qc^
I54O9Aoy
//线程睡眠 I [J0r
public static void sleep(int nSecond) ,T{(t@
{ pPm9v_G
try{ "Q~6cH[#
Thread.sleep(nSecond); |f^/((:D
} 27vLI~
catch(Exception e) 3mIX9&/
{ {.N" 6P
e.printStackTrace (); #lax0IYY=
} #zcp!WE.OI
} <%JRZYZ
,~Y5vnaOQ
//日志 #EpDIL
public static void log(String sMsg) N b(f
{ &/J[PdSb$
System.err.println(sMsg); mmXLGLMd
} |n;gGR\
YZCPS6PuE
-K`0`n}
public static void log(int sMsg) .~a)
{ %8kbX
System.err.println(sMsg); qFV=Pk
} =L$};ko
} J,fXXi)J
y@AKb
C"/]X
/* N1I1!!$K;%
**TestMethod.java [Bp[=\
*/ 5FHpJlFK,
package NetFox; $2F*p#l(<Z
:&dY1.<N+
j>M 'nQ,;d
public class TestMethod { &b}!KD1
/n7F]Ok'*
*?gn@4Ly
public TestMethod() "w`f>]YLA
{ ///xx/weblogic60b2_win.exe >]=1~sF
try{ I0O)MR<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Zg7~&vs$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); xZS
SiteFileFetch fileFetch = new SiteFileFetch(bean); :H<u@%
fileFetch.start(); ?T5^hQT
} _f,q8ZkSr
catch(Exception e){e.printStackTrace ();} >ofS'mp
:Qu!0tY
1+o>#8D
} "t8mQ;n
{!B0&x
TUZ-4{kV"
public static void main(String[] args) -(>x@];r0
{ B|%=<1?
new TestMethod(); amGQ!$] %#
} d {moU\W
} C4Q^WU+$j
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