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)); q1Qje%9@t
} S*W;%J5
for(int i=0;i<nEndPos.length-1;i++) 0O@_cW
{ y+mElG$F
nEndPos = nStartPos[i+1]; To"dG&h
} D=?{8'R'
nEndPos[nEndPos.length-1] = nFileLength; R zR?&J
} +`en{$%%
} wJ"ev.A)
}Ag|gF!_
AMlV%U#
//启动子线程 1IH[g*f
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; </oY4$l'
for(int i=0;i<nStartPos.length;i++) _uH9XGm
{ G"s0GpvQ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7|YrdK<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), M8W#io
nStartPos,nEndPos,i); Y)HbxFF`/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B+VuUt{S
fileSplitterFetch.start(); -/{af
} <HoAj"xf
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q|#MB7e/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); mMw;0/n
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ma8wmQ9JR
nEndPos = " + nFileLength); S)\8|ym6!
// fileSplitterFetch[nPos.length-1].start(); A=3HO\n5
y0q#R.TOm
s3t!<9[m
//等待子线程结束 Q}vbm4)[
//int count = 0; 'w<BJTQIL
//是否结束while循环 jp<VK<s]
boolean breakWhile = false; -e`;bX_N)
m@qqVRn#)
f@z*3I;
while(!bStop) -zfoRU v
{ D&{ *AH%Q
write_nPos(); b](o]O{v
Utility.sleep(500); 0Qd%iP)6
breakWhile = true; ym%slg
Df=q-iq<{/
TQ9'76INb
for(int i=0;i<nStartPos.length;i++) 1p\Ak
{ qc8Ta"
if(!fileSplitterFetch.bDownOver) 7[o {9Yp&
{ SE`l(-tL
breakWhile = false; (O5)wej
break; `.BR=['O
} UmP'L!
} 2R@%Y/
if(breakWhile) }=GM?,7b
break; &TT":FPR
V/y=6wUiSl
9{eBgdC
//count++; cH"@d^"+q|
//if(count>4) gbGTG(:1S
// siteStop(); |O (G nsZ
} HhSjR%6HY;
}p'8w\C$
=7jEz+w#
System.err.println("文件下载结束！"); l1-HO
} qi=3L
catch(Exception e){e.printStackTrace ();} :c4kBl%gJ
} kV)'a
Fj=NiZ=
0'yyfz
//获得文件长度 DX@}!6|T
public long getFileSize() FBYODw
{ km>o7V&4G
int nFileLength = -1; Npa-$N&P{S
try{ rz6jx
URL url = new URL(siteInfoBean.getSSiteURL()); *SZ>upg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }iNY_I c
httpConnection.setRequestProperty("User-Agent","NetFox"); \iZ1W
FMS2.E
njMLyT($
int responseCode=httpConnection.getResponseCode(); 9*_uCPR
if(responseCode>=400) 1%eLs=u?
{ /yYlu
processErrorCode(responseCode); xH$%5@~
return -2; //-2 represent access is error _T~H[&Hl
} =lrN'$z?%
8XbR
X<xqT
String sHeader; 878tI3-
h)o]TV
u2lmwE
for(int i=1;;i++) 37>MJ
{ H1Xovr
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,OB&nN t>
//Utility.log(in.readLine()); Nmf#`+7gCI
sHeader=httpConnection.getHeaderFieldKey(i); <nA3Sd"QfV
if(sHeader!=null) AQ}l%
{ 3wNN<R
if(sHeader.equals("Content-Length")) \{>eOD_
{ f[@#7,2~M
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :&$Xe1)i]
break; "jGe^+9uT
} tc/jY]'32
} dofR)"<p,^
else Mf7E72{D
break; >sV Bj(f
} :yD@5)
} c~oe,9
catch(IOException e){e.printStackTrace ();} I"V3+2e
catch(Exception e){e.printStackTrace ();} GTFl}t
UCF[oO>v
'%Dg{ zL
Utility.log(nFileLength); ZOHRUm
yS"0/Rm}
g =\13#F
return nFileLength; J~2CD*v
} m){&:Hs
}rxFS <j
M=Is9)y
//保存下载信息（文件指针位置） Na;t#,
private void write_nPos() N[{]iQ
{ D[W}[r
try{ 2$Y3[$
output = new DataOutputStream(new FileOutputStream(tmpFile)); h>Rpb#]
output.writeInt(nStartPos.length); )fR1n}#
for(int i=0;i<nStartPos.length;i++) UJs?9]x>
{ j)@oRWL<
// output.writeLong(nPos); nP)-Y#`~7
output.writeLong(fileSplitterFetch.nStartPos); 1 '%-y
output.writeLong(fileSplitterFetch.nEndPos); bgXc_>T6_y
} 2^ kn5
output.close(); |Kn^w4mN
} cFxSDTR
catch(IOException e){e.printStackTrace ();} [r~~=b7*[
catch(Exception e){e.printStackTrace ();} RA~_]Hk
} F~P/*FFK
c$.T<r)Z
P#9-bYNU
//读取保存的下载信息（文件指针位置） JgZdS-~
private void read_nPos() "U{mMd!9L
{ qZc)Sa.S
try{ gU*I;s>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >hesxC!
int nCount = input.readInt(); CY\mU_.b
nStartPos = new long[nCount]; y7 <(,uT
nEndPos = new long[nCount]; /^WE@r[:
for(int i=0;i<nStartPos.length;i++) '|+=B u
{ .Px,=56$X
nStartPos = input.readLong(); ^f"&}%"M
nEndPos = input.readLong(); 6P6Jx;
} k dUc&
input.close(); /3;=xZq
} 'jwTGT5x
catch(IOException e){e.printStackTrace ();} XAGiu;<,=
catch(Exception e){e.printStackTrace ();} $o::PDQ?
} w7[0
c{ZqQtfM
:4b- sg#
private void processErrorCode(int nErrorCode) m R"9&wq
{ 2fbvU
System.err.println("Error Code : " + nErrorCode); LDSbd,GF
} yl|R:/2V
aGe\.A=
Pyit87h{
//停止文件下载 r]Z.`}Kkm
public void siteStop() T&e%/
{ [kQ"6wh8
bStop = true; gB'`I(q5.
for(int i=0;i<nStartPos.length;i++) 1W4H-/Re
fileSplitterFetch.splitterStop(); %0go%_
P}b Dn;
\>_eEZ5
} &s_}u%iC
} 96k(XLR
//负责部分文件的抓取 ~c'\IM
**FileSplitterFetch.java + >Fv*lux
*/ VdYOm
package NetFox; :K5V/-[|V1
f2 VpeJ<p
FxMMxY,*%
import java.io.*; S:DcfR=a
import java.net.*; + 4++Z
O{O9}]6
7Co3P@@
public class FileSplitterFetch extends Thread { 6YB-}>?
~6=Wq64
%,h!: Ec^c
String sURL; //File URL ~p0e=u
long nStartPos; //File Snippet Start Position XP3QBq
long nEndPos; //File Snippet End Position "4k"U1
int nThreadID; //Thread's ID oTZo[T@zRx
boolean bDownOver = false; //Downing is over hlt9x.e.A
boolean bStop = false; //Stop identical lb=2*dFJ1
FileAccessI fileAccessI = null; //File Access interface BD<rQmfA^
k{!iDZr&f,
s$eK66H
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException D]3bwoFo&u
{ NO%|c|B|
this.sURL = sURL; nau~i1
this.nStartPos = nStart; zV9 =
this.nEndPos = nEnd; Ji)%Y5F
nThreadID = id; P DNt4=C
fileAccessI = new FileAccessI(sName,nStartPos);//定位 vWZ>Hf]`L
} m3x!*9h
@|JPE%T
)[F46?$vrk
public void run() jLpgWt`8)E
{ 1ZGQhjcx
while(nStartPos < nEndPos && !bStop) mJU>f-l
{ k|)^!BdO
[j]}$fFe
ZC>`ca
try{ N GX-'w
URL url = new URL(sURL); b*9m2=6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :C}KI)
httpConnection.setRequestProperty("User-Agent","NetFox"); $L $j KNwf
String sProperty = "bytes="+nStartPos+"-"; S+4I[|T]Y
httpConnection.setRequestProperty("RANGE",sProperty); YLr%vnO*NS
Utility.log(sProperty); _%C_uBLi
0$Qn#K
xV }:M
InputStream input = httpConnection.getInputStream(); Wl@0TUK
//logResponseHead(httpConnection); S S7D1
x|P<F2L
|sDG>Zq?
byte[] b = new byte[1024]; T=iZ9w
int nRead; w%!k?t,*]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .je~qo)
{ 5+#?7J1
nStartPos += fileAccessI.write(b,0,nRead); 10a=YG
//if(nThreadID == 1) =2GP^vh
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D~t"9Z\
} E#WjoIk
}-k_?2"A
98<bF{#0WM
Utility.log("Thread " + nThreadID + " is over!"); h[M6.
bDownOver = true; AOq9v~)z-
//nPos = fileAccessI.write (b,0,nRead); 3:z4M9f
} U[H+87zg
catch(Exception e){e.printStackTrace ();} N69eIdl
} BdRE*9.0
} _AsHw
D:S6Mu
DT1i2!
//打印回应的头信息 >8.v.;`
public void logResponseHead(HttpURLConnection con) ;8 /+wBnm
{ +)''l
for(int i=1;;i++) `i_L?C7
{ h<!khWFS
String header=con.getHeaderFieldKey(i); e2_r0I^C
if(header!=null) %$!R]B)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9Le/'ovq
Utility.log(header+" : "+con.getHeaderField(header)); v\r7.l:hf
else 8kn]_6:3i
break; HCn]#
} `eA&C4oFOO
} u:qD*zOq
~L Bq5a
VAG+y/q
public void splitterStop() zN8&M<mTl
{ LgD{!
bStop = true; ?Pok-90
} c=U$$|qHV
6#lC(ko'
_g/TH-;^
} /^es0$Co.
,EGD8$RA]
d >wmg*J
/* xSMp[j
**FileAccess.java SBYMDKZ
*//文件访问(定位，写) WEY97_@
package NetFox; p7ns(g@9
import java.io.*; W@uH!n>k
3Wtv+L7Br
^QL/m\zq@%
public class FileAccessI implements Serializable{ s5Bmv\e.i5
4jyr\=42F'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 wshp{ y
RandomAccessFile oSavedFile; qyG636i
long nPos; e8ig[:B>+
u^4"96aXJ
spoWdRM2
public FileAccessI() throws IOException (w@MlMk
{ eL$U M
this("",0); Kr}M>hF+|
} c#4L*$ViF
B$[%pm`'2
$y]||tX
public FileAccessI(String sName,long nPos) throws IOException ?}lpo; $
{ |?t8M9[Z
oSavedFile = new RandomAccessFile(sName,"rw"); >cr_^(UW&
this.nPos = nPos; >[P7Zlwv4
oSavedFile.seek(nPos); ws=9u-
} GVHfN5bTqn
+68K[s,FD
~)_ ?:.Da
public synchronized int write(byte[] b,int nStart,int nLen) :pF]TY"K.
{ O]r3?=
int n = -1; S&)) 0d
try{ re 1k]
oSavedFile.write(b,nStart,nLen); W$VCST
n = nLen; meVVRFQ2+
} QmkC~kK1.
catch(IOException e) 8UY=}R2C
{ pQ-^T.'
e.printStackTrace (); TWR#MVMI
} zl0:U2x7
}.|5S+J?[
cPBy(5^
return n; r(2'0JQ
} :R*^Izs=
UE$[;Zg
!7a^8
} &)f++(i
/KvPiQ%
m+8b2H:V
/* xS\QKnG.
**SiteInfoBean.java W<hdb!bE
*/ |I^Jn@Mq:
package NetFox; 9xS`@ "`
;>8TNB e!
+(P43XO08
public class SiteInfoBean { !DUg"o3G>
<{xAvN(:
byj mH
private String sSiteURL; //Site's URL G mUs U{
private String sFilePath; //Saved File's Path 41Q
private String sFileName; //Saved File's Name huD\dmQ:]
private int nSplitter; //Count of Splited Downloading File Rc.<0#
}GNH)-AG)$
n; '~"AG)
public SiteInfoBean() 'GdlqbX(%
{//nSplitter的缺省值为5 J]^gF|
//default value of nSplitter is 5 A%8`zR
this("","","",5); l|tp0[
} 3%4Mq6Q`
D.CsnfJ
Dmv
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $cpQ7
{ kkBV;v%a
sSiteURL= sURL; =28H^rK{
sFilePath = sPath; 1eyyu!
sFileName = sName; D}/.;]w<[&
this.nSplitter = nSpiltter; gx9sBkoq5D
KA{DN!
T2PFE4+Dp
} V5@[7ncVf
ue:P#] tx
vKOn7
public String getSSiteURL() 6{r[Dq
{ /ZN5WK
return sSiteURL; AdS_-Cm
} sU_4+Mk
]fS~N9B
&OR*r7*Z
public void setSSiteURL(String value) w[vIPlSdS
{ WHavz0knf[
sSiteURL = value; 5%aKlx9^#
} jqsktJw#i
@.@#WHde
i-vJ&}}
public String getSFilePath() tsC|R~wW
{ eKti+n.
return sFilePath; 2DqHqq9m
} SK}g(X7IWH
kQ'xs%Fw
? /X6x1PN
public void setSFilePath(String value) MC)W?
{ J0mCWtx&
sFilePath = value; dQ~"b=
} ]Tw6Fg1o>
QNa3S*
g UAPjR
public String getSFileName() qa`(,iN
{ A-!qO|E[-
return sFileName; R$m?&1K
} /,%o<Ql9
~e~Mx=FT0
z:jF)N
public void setSFileName(String value) WY~[tBi\
{ 1L qJ@v0
sFileName = value; rL/7wa
} He;%6OG{
]H'82a
*G|]5
public int getNSplitter() l8lR5<
{ .Tqvy)'
return nSplitter; wTbIS~!gF
} VOOThdR
*!s?hHv
/[dAgxL
public void setNSplitter(int nCount) ?+tZP3'
{ TmAb! Y|F
nSplitter = nCount; TBfl9Q
} ?\VN`8Yb
} !@1!ld
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emIbGkH
/* Pg C]@Q%
**Utility.java G"sc;nT
*/ m4LM10
package NetFox; RA67w&
X1D:{S[
X_8NW,
public class Utility { 6x8|v7cMH
wIHz TL
%d\+(:uu/
public Utility() A8Y~^wn
{ T`[ZNq+${
)`7h,w J[1
Ap9wH[H
} hrt-<7U
u#|Jl|aT
//线程睡眠 _Hj,;Z
public static void sleep(int nSecond) Oip..f0
{ %=eD)p7l-
try{ 3iL&;D
Thread.sleep(nSecond); iiB$<b.((I
} rWmi 'niu
catch(Exception e) M_I\:Q
{ .1lc'gu5y
e.printStackTrace (); l6Bd<tSH
} Bn:sN_N
} pz=Wq4l
xWV7#Z7
//日志 G<1mj!{Vp
public static void log(String sMsg) >(a_9l;q
{ Xq^{P2\w1
System.err.println(sMsg); " N4]e/.V
} niBpbsO
L]")TQ
4`]1W,t
public static void log(int sMsg) 1_]l|`Po
{ e|y~q0Q$
System.err.println(sMsg); w Vmy`OV/
} nzDY!Y
} mn` Ae=
HEN9D/O=
U%l{>*q
/* .C?gnOq
**TestMethod.java nJC}wh2d#
*/ b7mP~]V
package NetFox; &T}e93]
}$U6lh/Ep
]h@:Y]
public class TestMethod { OSU=O
Q)&Ztw<
mj~CCokF{?
public TestMethod() _;W|iUreb
{ ///xx/weblogic60b2_win.exe }qPo%T
try{ 8^T$6A[b
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {eV_+@dT
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _Z&R'`kg
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;_*F [ }w
fileFetch.start(); Pp!W$C:
} `BY`ltW
catch(Exception e){e.printStackTrace ();} eD0@n :
k/O&,T77}J
en)DN3
} b L~<~gA
eyV904<F
.jw)e!<\N
public static void main(String[] args) =Y0m;-1M
{ MvFXVCT#
new TestMethod(); RR|Eqm3)
} .EQFHStr
} RJM(+5xQ|
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