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)); .KRh59yg
} 1N:eM/a
for(int i=0;i<nEndPos.length-1;i++) !BK^5,4?--
{ %{o5}TqD
nEndPos = nStartPos[i+1]; tTQ>pg1{qh
} B`T9dL[E4
nEndPos[nEndPos.length-1] = nFileLength; nQ/(*d
} r1F5&?{q
} y"2#bq
tEf-BV;\y
NIV&)`w
//启动子线程 ?uh7m2l0D
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5+,&9;'Y^
for(int i=0;i<nStartPos.length;i++) pMs%`j#T
{ 6=|Q>[K
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), E/5w H/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?WUu@Z
nStartPos,nEndPos,i); %T1(3T{Li
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ))306*X\
fileSplitterFetch.start(); kk^KaD4dA
} Vf O0 z5&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2BRY2EF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Pm" ,7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `q4\w[0+p
nEndPos = " + nFileLength); ydoCoD w
// fileSplitterFetch[nPos.length-1].start(); \kC/)d
m#'u;GP]k
w[]7{D];
//等待子线程结束 -C.eXR{s
//int count = 0; gIRFqEz@o
//是否结束while循环 b\6w[52m
boolean breakWhile = false; `[CXxp
/XnI>
bha_bj
while(!bStop) wGb{O
{ P+oCcYp
write_nPos(); [.|tD
Utility.sleep(500); ]$KH78MTW
breakWhile = true; 0'aZ*ozk
S(/@.gI:f
5E}0<&
for(int i=0;i<nStartPos.length;i++) H^'EY:|
{ Q:@Y/4=
if(!fileSplitterFetch.bDownOver) #YjV3O5<
{ 9u"im+=:
breakWhile = false; ZLo3 0*
break; rpy`Wz/[
} I"Y?vj9]
} 31J7# S2
if(breakWhile) pE15[fJ`
break; .8fOc.h8h
N[zI@>x
7r*>?]y+
//count++; ib uA~\5
//if(count>4) x{RTI#a.
// siteStop(); n |.- :Zy
} q;Qpd]H
F'|,(P
(7-K4j`
System.err.println("文件下载结束！"); gY;N>Yq,C
} %xWmzdn
catch(Exception e){e.printStackTrace ();} 9Q].cDe[
} &[JI L=m5
bNIT 1'v
1gH5#_?
//获得文件长度 QT^( oog=
public long getFileSize() [xM07%:
{ )mwY] !
int nFileLength = -1; G{ F>=z"(l
try{ m0/J3
URL url = new URL(siteInfoBean.getSSiteURL()); O(WFjmHx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =ngu*#?c4
httpConnection.setRequestProperty("User-Agent","NetFox"); A+Z3b:}~
h-!(O^M
&tp5y}=n
int responseCode=httpConnection.getResponseCode(); Wpj.G
if(responseCode>=400) -YSn 3=
{ (;Lz`r'
processErrorCode(responseCode); F)v+.5T1
return -2; //-2 represent access is error @{t^8I#]
} I~4`NV0
<*4=sX@
`1pri0!
String sHeader; 5)&e2V',y
F~RUb&*/<
gU+BRTZ&x
for(int i=1;;i++) APK@Oq
{ V 9=y@`;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); NP%ll e,l
//Utility.log(in.readLine()); *7!}[ v_
sHeader=httpConnection.getHeaderFieldKey(i); US> m1KsX
if(sHeader!=null) d7KeJ$xy}p
{ Y^3tk}yru
if(sHeader.equals("Content-Length")) hRc\&+#/
{ P+"#xH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _k6N(c2Nd
break; UP,0`fh(y
} Jz3q Pr
} ojyG|Y
else j|+B|
break; 5O)Z}
} HJ_xg6.x
} #1m!,tC
catch(IOException e){e.printStackTrace ();} 1d-j_H`s
catch(Exception e){e.printStackTrace ();} [C7:Yg7
RZ?>>Ll6
paMw88*u
Utility.log(nFileLength); yd>kJk^~/
Prjl ;[I}
D8Ni=.ALL
return nFileLength; 3OM\R%M
} 'OF)`5sj
cH2 nG:H
<_42h|-
//保存下载信息（文件指针位置） fI}-?@
private void write_nPos() a&Z|3+ZA
{ U*1~Zf
try{ t'[vN~I'
output = new DataOutputStream(new FileOutputStream(tmpFile)); ugMJ}IGq
output.writeInt(nStartPos.length); LM*9b
for(int i=0;i<nStartPos.length;i++) EH4WR/x
{ ,[cWG)-
// output.writeLong(nPos); &dOV0y_
output.writeLong(fileSplitterFetch.nStartPos); FK mFjqY
output.writeLong(fileSplitterFetch.nEndPos); ^!kvgm<{$
} $g1p!
output.close(); ]=]'*Z%
} eeL%Yp3+
catch(IOException e){e.printStackTrace ();} Uhg[#TUK
catch(Exception e){e.printStackTrace ();} )FU4iN)ei
} U][.ioc
)Hev-C"
o8Bo%OjE
//读取保存的下载信息（文件指针位置） O`@$YXuD
private void read_nPos() c~$ipX
{ CQv [Od
try{ Tri.>@-u
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .h7b 4J
int nCount = input.readInt(); VN$#y4
nStartPos = new long[nCount]; n,AN&BZ
nEndPos = new long[nCount]; *w@>zkBl
for(int i=0;i<nStartPos.length;i++) mZq*o<kTA
{ =U,;/f
nStartPos = input.readLong(); tQwbIX-7/
nEndPos = input.readLong(); ~t#'X8.)
} +mF}j=k
input.close(); oh:t ex<
} kg !@i7
catch(IOException e){e.printStackTrace ();} uO":\<1#
catch(Exception e){e.printStackTrace ();} "BzRLg!J
} px-*uh<
x80~j(uVf
F92n)*[
private void processErrorCode(int nErrorCode) Y-,#3%bT;;
{ O#k?c }
System.err.println("Error Code : " + nErrorCode); `ZNjA},.
} xt3IR0
w$&10
c)$/Uu
//停止文件下载 Hq%`DWus\
public void siteStop() Qs,LK(1
{ `NGCUGQ_7
bStop = true; "M?(Ax
for(int i=0;i<nStartPos.length;i++) *qq%)7
fileSplitterFetch.splitterStop(); O %)+ w
_$, .NK,6
g8vN^nQf[
} uF<F4m;
} \kg2pF[V
//负责部分文件的抓取 @AyC0}
**FileSplitterFetch.java h,\_F#hi
*/ A\:=p
package NetFox; ^ qE4:|e
#s]]\
sA` bPhk
import java.io.*; O:u^jcXA
import java.net.*; ;APg!5X
g0iV#i
zlXkD~GV
public class FileSplitterFetch extends Thread { UQTt;RS*zS
bu$5gGWVf
_@d.wfM
String sURL; //File URL .JH3,L"S^
long nStartPos; //File Snippet Start Position 9g 2x+@5T^
long nEndPos; //File Snippet End Position `N|WCiBV.
int nThreadID; //Thread's ID O'!k$iJNb
boolean bDownOver = false; //Downing is over S'?XI@t[
boolean bStop = false; //Stop identical %3kqBH!d
FileAccessI fileAccessI = null; //File Access interface %VwB ?
d/* [t!
FiIN\
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException B8;ZOLAU
{ 7dW9i7Aj
this.sURL = sURL; R?I(f(ib
this.nStartPos = nStart; nYE_WXY3V
this.nEndPos = nEnd; 27Lya!/
nThreadID = id; RtF_p {s
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Rfgc^3:j
} *y`^Fc
Ebp8})P/~
op}x}Ioz
public void run() ,Cx5( ~kU
{ (}Gl'.>\M
while(nStartPos < nEndPos && !bStop) 3`="4
{ 5bMVDw/
EJL45R>
)V9$ P)
try{ La3f{;|u5M
URL url = new URL(sURL); ~6@~fhu
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *]F3pP[
httpConnection.setRequestProperty("User-Agent","NetFox"); ^t#]E#
String sProperty = "bytes="+nStartPos+"-"; `uGX/yQ#=
httpConnection.setRequestProperty("RANGE",sProperty); 8xL-j2w
Utility.log(sProperty); 3+!N[6Od9
5#:tL&q
t}TtWI
InputStream input = httpConnection.getInputStream(); ^DIN(0u)
//logResponseHead(httpConnection); `ORDN|s6
>5]Xl*{H)
,g^Bu{?
byte[] b = new byte[1024]; "7gS*v,r
int nRead; 9}3W0F;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @NX^__sa
{ |nocz]yU$
nStartPos += fileAccessI.write(b,0,nRead); zwAuF%U
//if(nThreadID == 1) \'1%"JWK
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (<1DPpy95O
} )vy<q/o+
{feS-.Khv
c*6o{x}K
Utility.log("Thread " + nThreadID + " is over!"); zRsA[F#
bDownOver = true; ,Hp9Gkm8I/
//nPos = fileAccessI.write (b,0,nRead); [i&z_e)
} (U-p&q>z
catch(Exception e){e.printStackTrace ();} [IW@mn>
} 9:@os0^O
} >)5rOU
J-u,6c
L{(r@Vu
//打印回应的头信息 }rGDM
public void logResponseHead(HttpURLConnection con) c*\^61T
{ *TMg.
for(int i=1;;i++) 6bqJM#y@
{ Jr1^qY`0+
String header=con.getHeaderFieldKey(i); +ES.O]?>
if(header!=null) zBc7bbK
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0.+iVOz+Y
Utility.log(header+" : "+con.getHeaderField(header)); xD_jfAH'
else -=g`7^qa>
break; YQ?|Vb U
} Y!Z@1V`
} MjG.Ili$m
',O@0L]L
bfa5X<8
public void splitterStop() iJsw:Nc
{ h`n>6I
bStop = true; OU{PVF={
} X>Xpx<RY!
0@xuxm/i
V=S`%1dLN
} 'TbA^U[
r Ssv^W+
J(l6(+8
/* 2y<d@z:K
**FileAccess.java z?7s'2w&{
*//文件访问(定位，写) otPEJ^W&
package NetFox; [NKWudq
import java.io.*; ^_<pc|1
M)b`~|Wt
Th!S?{v
public class FileAccessI implements Serializable{ NZ.aI{
f0hi70\(X
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 } g
RandomAccessFile oSavedFile; ow`\7qr
long nPos; h@Hmo^!9J
xt`znNN
3@}_ F<"*
public FileAccessI() throws IOException ?2G^6>O`
{ '.^JN@
this("",0); :;|x'[JoE?
} RF6|zCWuI
r+Z+x{
/\\C&Px
public FileAccessI(String sName,long nPos) throws IOException 7tr.&A^c
{ :m+:%keK
oSavedFile = new RandomAccessFile(sName,"rw"); wr#+q1v
this.nPos = nPos; [jLx}\]
oSavedFile.seek(nPos); &GbCJ
} k}<mmKB
rhUZ9Fdv
f,?7,?x
public synchronized int write(byte[] b,int nStart,int nLen) RGxOb
{ "<.b=mN-
int n = -1; =+"XV8Fi,
try{ 82w<q(
oSavedFile.write(b,nStart,nLen); wYF)G;[wM
n = nLen; Dic(G[
} xbmOch}j6
catch(IOException e) CiMN J
{ W>,b1_k c
e.printStackTrace (); }k,Si9O
} FEP\5d>
xt-;7
#p[=iP
return n; 1`)R#$h
} Sa@Xh,y Z
0u0Hl%nl
I4");T3
} t Y^:C[
&0o&!P8CB
P|6m%y
/* T$q]iSgu
**SiteInfoBean.java 66BsUA.h
*/ iI_Fbw8
package NetFox; z#-&MJ
*.K}`89T
9^}GUJy?
public class SiteInfoBean { VX- f~
h<QXr'4+
V&f3>#n\
private String sSiteURL; //Site's URL [PU.lRq
private String sFilePath; //Saved File's Path fNlUc
private String sFileName; //Saved File's Name .jRXHrK;
private int nSplitter; //Count of Splited Downloading File $U6)km4
gmM79^CEF
K3@UoR
public SiteInfoBean() 4+uAd"
{//nSplitter的缺省值为5 mM95BUB
//default value of nSplitter is 5 \"uR&D
this("","","",5); &-{4JSII
} j0OxR.S
OgzPX^q/=
KQ2]VN"?_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $60+}B`m
{ &K\di*kN
sSiteURL= sURL; B,A/ -B\
sFilePath = sPath; &-&6ARb7o
sFileName = sName; ^h' wZ7-\
this.nSplitter = nSpiltter; {0[qERj"z
XCk \#(VSE
>uI|S
} iveWau292
T}zOM%]]
2B*9]AHny
public String getSSiteURL() '\\J95*`
{ 4w\')@`[jk
return sSiteURL; J \G8g,@
} BG=h1ybz
{o;J'yjre1
Z*leEwgz
public void setSSiteURL(String value) `s.y!(`q
{ @(ev``L5g
sSiteURL = value; !,I}2,1%k
} CjD2FnjT
j]kx~
\N!k)6\
public String getSFilePath() ;Qw>&24h[
{ i8EMjLBUR
return sFilePath; P=eL24j
} I]zCsT.
O'_D*?
TqzkF7;k4
public void setSFilePath(String value) 2#p6.4h=
{ >/-<,,<\C
sFilePath = value; \-c70v63X
} l'mgjv~
St'3e<
D4[t@*m>7
public String getSFileName() !m:SRNPg
{ ECQ>VeP
return sFileName; 29}(l#S}m
} ;CFI*Wfp
`WX @1]m
^ WidA-
public void setSFileName(String value) ^!?W!k!:V
{ UoBmS5
sFileName = value; 1Hk`i%
} I6zKvP8pb
XWH~o:0<2
[gx6e 44
public int getNSplitter() 0c /xE<h
{ |3QKxS0
return nSplitter; "Lw[ $
} @tR:}J*9s
FK{Vnj0
g>u{H:
public void setNSplitter(int nCount) aF]4%E
{ T}M!A|
nSplitter = nCount; ^FIpkhw
} sWa`-gc
} MV'q_{J
aHuZzYQ*"j
Xy5#wDRC
/* $oDc
**Utility.java O3x9S,1i
*/ !?#B*JGFS
package NetFox; >cpT_M&C,
:2ILN.&
k[#<=G_=/E
public class Utility { FN0)DN2d}
Qqm'Yom%T
d< j+a1&
public Utility() 9EHhVi
{ A6eIf
z_nv|5"
YS],o'T
} 40h
"Tt5cqUQoY
//线程睡眠 ?V&#nA
public static void sleep(int nSecond) w>S;}[fM
{ `X)y5*##wq
try{ Z{XF!pS%H
Thread.sleep(nSecond); |2AMj0V~
} {+Zj}3o
catch(Exception e) [A\DuJx
{ )IBvm1
e.printStackTrace (); 9 n0?0mk
} c`,'[Q5(O
} C}jFR] x)
*3@ =XY7
//日志 [Z]%jABR
public static void log(String sMsg) n Nu~)X
{ G'#Uzwo
System.err.println(sMsg); 7!sR%h5p
} wHuz~y6
S/,)X
CWdpF>En
public static void log(int sMsg) LS:^K
{ 0q6xXNAX
System.err.println(sMsg); :;Xh`br
} {e!3|&AX
} &TTvX%T
:@@aIFRv
"UYlC0 S\
/* X*w7q7\8-:
**TestMethod.java Se}&2 R
*/ YQ|o0>
package NetFox; w!_6*
J.(mg D
ZHM NG~!
public class TestMethod { =JaxT90x
Nr"gj$v
.k -!/^
public TestMethod() }vxRjO,
{ ///xx/weblogic60b2_win.exe .^xQtnq
try{ * ,Le--t
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Cy\ o{6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); (M#m BS
SiteFileFetch fileFetch = new SiteFileFetch(bean); \MDhm,H<
fileFetch.start(); %bp'`B=
} 7Y.mp9,
catch(Exception e){e.printStackTrace ();} Z&|Dp*Z
7Hg;SK6t0
Y)68
} G:!3X)b
nxJx8d"
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public static void main(String[] args) R8>17w.
{ Gs/G_E(T
new TestMethod(); =4uO"o
} $\#wsI(
} q{}U5(,{0
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