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)); ?vt#M^Q
} )7]la/0
for(int i=0;i<nEndPos.length-1;i++) x{DTVa 6y2
{ K@%o$S?>z_
nEndPos = nStartPos[i+1]; 0JT"Pv_
} D/[;Y<X#V
nEndPos[nEndPos.length-1] = nFileLength; n?Zt\Kto
} Gh%R4)}
} u,RR|/@
=csh=V@s
H4B|c42
//启动子线程 :j2?v(jT_l
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 21k,{FB'?
for(int i=0;i<nStartPos.length;i++) '/="bSF
{ [~NJf3c"
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j(~e{HZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), uB=DC'lkg
nStartPos,nEndPos,i); t=nZ1GZyM
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,V^2Oa
fileSplitterFetch.start(); k3(q!~a:.}
} QmgO00{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lA{JpH_Y8s
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .;\uh$c
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", B4@1WZn<8
nEndPos = " + nFileLength); e&@;hDmIX
// fileSplitterFetch[nPos.length-1].start(); L"KKW c
knfEbH
MJ"@
//等待子线程结束 %$Dn);6=
//int count = 0; VLPPEV-u
//是否结束while循环 b>h L*9
boolean breakWhile = false; gmqA 5W~y
&]"Z x0t5%
'XJqh|G
while(!bStop) LZtO Q__B)
{ E"%dO
write_nPos(); |LV}kG(2
Utility.sleep(500); t:x"]K
breakWhile = true; C/?x`2'
j>8S,b=%
n'To:
for(int i=0;i<nStartPos.length;i++) a B$x(8pP@
{ DD5cUlOSu
if(!fileSplitterFetch.bDownOver) LpK? C<?x
{ >P+oNY
breakWhile = false; %i6/= 'u
break; uc{s\_
} Pm7lP5
} 7}1Z7"?
if(breakWhile) R]&lVXyH
break; S5BS![-QK
L35]'Jua
enGZb&
//count++; ~9y/MR
//if(count>4) 9!_JV;2
// siteStop(); r^7eK)XA_
} /HH_Zi0?N|
.wV-g:2
;il+C!6zpf
System.err.println("文件下载结束！"); A]laS7Q
} 00B,1Q HP
catch(Exception e){e.printStackTrace ();} 82)%`$yZw[
} e'yw8U5E/
]GT+UX
>*/:"!u
//获得文件长度 w5 #;Lm
public long getFileSize() NR,R.N^[
{ wRdN(`;v
int nFileLength = -1; EK.n $
try{ {%_D>y
URL url = new URL(siteInfoBean.getSSiteURL()); \9fJ)*-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eZ]>;5
httpConnection.setRequestProperty("User-Agent","NetFox"); j[Jwa*GQP
V%(T#_E/6
An_3DrUFV_
int responseCode=httpConnection.getResponseCode(); U3jnH
if(responseCode>=400) xS4?M<|L63
{ 63(XCO
processErrorCode(responseCode); OI_Px3) y
return -2; //-2 represent access is error Co,?<v=Ll
} 2#
P~#LbUP(
SdF+b+P]
String sHeader; d\R "?Sg
1#3eY?Nb
K]1|#`n
for(int i=1;;i++) n&!q9CR`
{ )(OGo`4Qz
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ^RE[5h6^q
//Utility.log(in.readLine()); L&KL]n
sHeader=httpConnection.getHeaderFieldKey(i); v.ow`MO=;
if(sHeader!=null) .HN4xL
{ *k,{[b
if(sHeader.equals("Content-Length")) t7yvd7
{ LSR0yCU
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); i=R%MH+
break; K8/jfm
} !UR3`Xk
} Y(] W+k<
else #)#J`s1R
break; 1LaJ hrp?
} T_qM@/f
} e7y,zcbv
catch(IOException e){e.printStackTrace ();} SQ*%d.1
catch(Exception e){e.printStackTrace ();} c'XSs
m70AWG
.+mP#<mAg
Utility.log(nFileLength); Lf:#koaC
guVuO
,k1ns?i9KH
return nFileLength; p-m\0tQ
} G)?j(El
<00nu'Ex1v
R_9M-RP6*
//保存下载信息（文件指针位置） ]*U+nG
private void write_nPos() #)m[R5g(
{ 62kA(F0e,
try{ XTA:Y7"O
output = new DataOutputStream(new FileOutputStream(tmpFile)); #]QS
output.writeInt(nStartPos.length); V*r/0|vd
for(int i=0;i<nStartPos.length;i++) }+}Cl T
{ L{GlDoFk
// output.writeLong(nPos); Z<W f/
output.writeLong(fileSplitterFetch.nStartPos); CfO{KiM(2
output.writeLong(fileSplitterFetch.nEndPos); P'[ISGt
} z}iz~WZ
output.close(); fu{v(^
} vM-kk:n7f
catch(IOException e){e.printStackTrace ();} KYyoN
catch(Exception e){e.printStackTrace ();} Q@|"xKa
} r"7PSJ
tJ*/5k &
\Unawv~
//读取保存的下载信息（文件指针位置） {3SK|J`
private void read_nPos() <Qr*!-Kc6
{ elR1NhB|p
try{ Bp5%&T k
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t<"`gM^|
int nCount = input.readInt(); m;nH v
nStartPos = new long[nCount]; 9ei<ou_s
nEndPos = new long[nCount]; QCG-CzJ9l
for(int i=0;i<nStartPos.length;i++) ;dtA-EfOZ
{ VU6+"2+'2
nStartPos = input.readLong(); Lctp=X4
nEndPos = input.readLong(); 9=FH2|Z
} mKE'l'9A_
input.close(); oKr= ]p
} z8r?C
catch(IOException e){e.printStackTrace ();} $m-C6xC/
catch(Exception e){e.printStackTrace ();} C8i4z
} K47.zu
,<C~DSAyZ
>l=jJTJ;q
private void processErrorCode(int nErrorCode) rLY I\
{ I.Xbowl
System.err.println("Error Code : " + nErrorCode); C?MKbD=K
} zlB[Eg^X
\acGSW .c
ny!80I
//停止文件下载 ,-kz\N@.
public void siteStop() M04u>| ,
{ fOKAy'
bStop = true; =*.S<Ko)
for(int i=0;i<nStartPos.length;i++) z =\ENG|x#
fileSplitterFetch.splitterStop(); DZ $O%
i+Mg[x$.
|MN2v[y
} Bs|#7mA[
} hhhxsGyv
//负责部分文件的抓取 @$CPTv3e
**FileSplitterFetch.java 6(7dr?^eGT
*/ ;mr*$Iu7|
package NetFox; >L8 &6aU
0+)1KU)I
@*uZ+$
import java.io.*; !HtW~8|:
import java.net.*; oA:`=f%\
. Y$xNLoP[
{d0 rUHP
public class FileSplitterFetch extends Thread { I)9,
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f+.sm
String sURL; //File URL +QOK]NJN
long nStartPos; //File Snippet Start Position Jh36NE8r
long nEndPos; //File Snippet End Position 0W_u"UY$c
int nThreadID; //Thread's ID GuaF B[4
boolean bDownOver = false; //Downing is over ({$rb-
boolean bStop = false; //Stop identical &os:h] C
FileAccessI fileAccessI = null; //File Access interface ~$rSy|19
mVN\
(dy:d^
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _PQk<QZ
{ <]_[o:nOP
this.sURL = sURL; ^rO!-
this.nStartPos = nStart; }[PC YnS
this.nEndPos = nEnd; 7AqbfLO
nThreadID = id; z5D*UOy5M
fileAccessI = new FileAccessI(sName,nStartPos);//定位 C[l5[DpH
} J l{My^I5
T11>&K)
Q~n%c7
public void run() _KBa`lhE
{ \/nSRAk
while(nStartPos < nEndPos && !bStop) ~]9EhC'l
{ cXr_,>k
I"QU{]|J
|+JC'b?,
try{ ccx0aC3@I
URL url = new URL(sURL); }AiF 7N0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z.rhM[*+0C
httpConnection.setRequestProperty("User-Agent","NetFox"); >z%WW&Z'
String sProperty = "bytes="+nStartPos+"-"; T.B7QAI. H
httpConnection.setRequestProperty("RANGE",sProperty); wbk$(P'gN
Utility.log(sProperty); ytb1hFs
S)'&+HamI
r%>7n,+o
InputStream input = httpConnection.getInputStream(); OHnsfXO_V
//logResponseHead(httpConnection); glkH??S
7j(gW
MX+gc$Y O
byte[] b = new byte[1024]; w4&\-S#
int nRead; b`}hw"f
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Z Y5Pf 1
{ x2/ciC
nStartPos += fileAccessI.write(b,0,nRead); 8o).q}>&
//if(nThreadID == 1) +1\t0P24
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m,6[;
} fEtBodA)
7h:EU7
^gY'^2bzxu
Utility.log("Thread " + nThreadID + " is over!"); /YvwQ
bDownOver = true; jfam/LL{V
//nPos = fileAccessI.write (b,0,nRead); Adfnd
} r;>.*60AT
catch(Exception e){e.printStackTrace ();} hvA|d=R(
} m%.[|sZ3EM
} gO@LJ
uu>R)iTQ%S
Zw<<p|{)<
//打印回应的头信息 ?+%bEZ`
public void logResponseHead(HttpURLConnection con) ; 3sjTqD
{ FF|M7/[~
for(int i=1;;i++) [o7Qr?RN
{ :2XX~|
String header=con.getHeaderFieldKey(i); sv#b5,>9
if(header!=null) s"2+H}u
//responseHeaders.put(header,httpConnection.getHeaderField(header)); g0IvcA
Utility.log(header+" : "+con.getHeaderField(header)); VCIV*5 P
else I= cayR
break; PIoBKCJ
} ^V]IPGV
} A^zd:h-
M=4b
TZ}y%iU:mB
public void splitterStop() m}>Q#IVZ
{ A>RK3{7
bStop = true; }gE^HH'
} 6!;D],,"#.
k\g:uIsv$
vWL|vR
} glBS|b$\:
$ERiBALN:
|8)\8b|VuC
/* IP)%y%ycw
**FileAccess.java I%B\Wy/j^
*//文件访问(定位，写) x`2du/ C
package NetFox; gr# |ZK.`
import java.io.*; s3K!~v\L]
'tjqfR
>Nx4 +|
public class FileAccessI implements Serializable{ 9;L8%T (
K<50>uG
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :YLurng/]
RandomAccessFile oSavedFile; k[@/N+;")`
long nPos; ~]'yUd1gSZ
gg Nvm
*D1vla8
public FileAccessI() throws IOException 1(e64w@
{ .SNg2.
this("",0); \Xr*1DI<
} >t%@)]*N
IlB*JJnl
.Sv/0&O
public FileAccessI(String sName,long nPos) throws IOException k]2_vk^
{ MN:LL <
oSavedFile = new RandomAccessFile(sName,"rw"); E Q:6R|L
this.nPos = nPos; |=V~CQ]
oSavedFile.seek(nPos); y'non0P.
} >Pvz5Hf/wW
vskp1Wi(
upZf&4 I8
public synchronized int write(byte[] b,int nStart,int nLen) &VG
{ iqN?'8
int n = -1; ^ohIJcI-
try{ c: (nlYZ
oSavedFile.write(b,nStart,nLen); #]Jg>
n = nLen; }d5~w[
} O]Yz7
catch(IOException e) r@ !
{ H?V b
e.printStackTrace (); 6)>otB8)J
} U\-R'Z>M
rZ2cC#
_6g(C_m'T?
return n; ${gO=Z
} ?},RN
$ ?|;w,%I
=hY/Yr%P
} s#(%u t
H5o=nWQ6e
;kT~&.,y
/* 8Dn~U:F/?
**SiteInfoBean.java wzBw5nf\
*/ py'xBi6}v
package NetFox; )t CNp
sk AF6n
{i}E)Np
public class SiteInfoBean { k+Z2)j"
[khXAf1{Q
zJ@^Bw;A^@
private String sSiteURL; //Site's URL ntW1 )H'o
private String sFilePath; //Saved File's Path S,Tc\}
private String sFileName; //Saved File's Name QZ*gR#K]Sz
private int nSplitter; //Count of Splited Downloading File [ugr<[6
MV07RjeS
G&"O)$h
public SiteInfoBean() t+{vbS0
{//nSplitter的缺省值为5 '|<S`,'#hg
//default value of nSplitter is 5 &:1q3gDm
this("","","",5); \xQu*M:!
} 7:<A_OLi
+oL@pp0
\1QY=}
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) G.PRPl
{ 'K#ndCGJ$
sSiteURL= sURL; %joL}f[
sFilePath = sPath; JV_VM{w{K
sFileName = sName; T;V!>W37
this.nSplitter = nSpiltter; Xg*](>/\,
V)vik
8IE^u<H(:
} u(\O@5a
-Zp BYX5e_
!SIk9~rJ
public String getSSiteURL() sV\K[4HG
{ e6^}XRyf
return sSiteURL; 2U(qyC
} 0N$FIw2
%$i}[U
[^^Pl:+
public void setSSiteURL(String value) TwI'XMO;A
{ qI${7
sSiteURL = value; 6CSoQ|c{
} 0%4OmLBT
%%zlqd"0
e[0"x.gu
public String getSFilePath() `csZ*$7
{ p@[ fZj
return sFilePath; <fV][W
} yc`*zLWh
J0oeCb
+-,iC6kK
public void setSFilePath(String value) Vjw u:M
{ euVj,m
sFilePath = value; -3guuT3x\
} iq[IZdza
xc\zRsY`
d325Cw?
public String getSFileName() F\L!.B
{ D/GE-lq
return sFileName; RBBmGZ
} >k/cm3
8/&4l,M5
51y#AQ@
public void setSFileName(String value) _A])q
{ ic"8'Rwb
sFileName = value; tC5-^5[y
} UGj |)/
n.z,-H17
'+27_j
public int getNSplitter() ${eV3LSC
{ QWEE%}\3}
return nSplitter; 0U H]
} \4^rb?B
(<8}un
c?u*,d) G
public void setNSplitter(int nCount) ,wXmJ)/WZ
{ )*S:C
nSplitter = nCount; Kf*Dy:e
} G$%F`R[
} .Y"F3 R
32j}ep.*
rNTLP m
/* C4P<GtR9
**Utility.java 0bT[05.
*/ KIag(!&
package NetFox; Wpi35JrC
[uLsM<C
4+s6cQ]S`
public class Utility { u3GBAjPsIk
~BX=n9
[/%N2mj
public Utility() e}S+1G6r)
{ f'H|K+bO
^gZ,A]
d7 H*F
} /XEW]/4
JXYZ5&[
//线程睡眠 ~x#TfeU]
public static void sleep(int nSecond) "=T&SY
{ dRnf
try{ nP]!{J]
Thread.sleep(nSecond); _lFw1pa#\
} l $"hhI8
catch(Exception e) $2?j2}M
{ fe,6YXUf
e.printStackTrace (); mbGma
} kFV, Fg
} . R/y`:1:W
j)6p>6
//日志 yxo=eSOM
public static void log(String sMsg) ,^97Ks ;
{ 0FgF,
System.err.println(sMsg); ;%B9mM#p~
} 6/Xs}[iJ
,3y9yJQa*#
Z>Mv$F"p:
public static void log(int sMsg) 2R.LLE
{ _Uq' N0U
System.err.println(sMsg); <.B+&3')
} }$4z$&
} v|o{AL:ei
~~Ezt*lH
yi>AogQ,
/* . yg#
**TestMethod.java Cl]?qH*:
*/ @XV&^l-
package NetFox; '.(Gg%*\.
o1x1SH
b' y*\9Ru
public class TestMethod { q1( [mHZ
n]ba1t8ZA
'=n?^EPE3
public TestMethod() 4^F%bXJ)
{ ///xx/weblogic60b2_win.exe N+rU|iMa.
try{ '#Au~5
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =I@t%Y
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]f0'YLG
SiteFileFetch fileFetch = new SiteFileFetch(bean); .Dr!\.hL
fileFetch.start(); c{BAQZVc
} wG3b{0
catch(Exception e){e.printStackTrace ();} =abcLrf2G
?<TJ}("/
89g a+#7
} JfIXv
MK=oGzK
0lg$zi x(
public static void main(String[] args) H.@$#D
{ 2Jd(@DcJ2C
new TestMethod(); u;-&r'J>
} +*]$PVAFA
} iM)K:L7d
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