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)); pmwVVUEQ
} =-bGH
for(int i=0;i<nEndPos.length-1;i++) 5}C.^J`
{ qTZ\;[CrP"
nEndPos = nStartPos[i+1]; :Oiz|b(
} ml,FBBGq|-
nEndPos[nEndPos.length-1] = nFileLength; eR3v=Q
} kI?+\k\V`
} u*}ltR~/
YuXCRw9p;
<?Ln`,Duk
//启动子线程 pl}nbY
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; C]EkVcKFA
for(int i=0;i<nStartPos.length;i++) *c<6 Er>s
{ OI^??joQ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^ YOCHXg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), W{RZ@3ZY
nStartPos,nEndPos,i); HOaNhJ{7D
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); JtvZ~s
fileSplitterFetch.start(); #7Fdmnu`
} ^%n]_[RUn4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vmzc0J+3p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); YjCHKI"e
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", q@Aw]Kh
nEndPos = " + nFileLength); @>fsg-|
// fileSplitterFetch[nPos.length-1].start(); *"nN To
hv0bs8h
oyT`AYa
//等待子线程结束 dy>5LzqK3
//int count = 0; K/iFB
//是否结束while循环 : E`78
boolean breakWhile = false; n1U!od
\wV^uS
XL3m#zW&
while(!bStop) <Hf3AB;#4
{ G{.[o6>
write_nPos(); c>Tf@Aog>
Utility.sleep(500); UY6aD~tD0
breakWhile = true; 2U|"]tpM&
)2lB
i/.#`
for(int i=0;i<nStartPos.length;i++) =,b6yV+$D
{ .C\2f+(U
if(!fileSplitterFetch.bDownOver) 1=Kt.tuf
{ ^IgQIN
breakWhile = false; "T$LJ1E
break; dl.gCiI
} Cag^$nj
} w}]BJ<C
if(breakWhile) S zNZY&8 f
break; Bs`mzA54
?edf$-"z/
{'Y()p3kl
//count++; ;`O9YbP#
//if(count>4) \G#_z|'dN
// siteStop(); 5X>K#N
} c/7}5#Rs
h`dHk]O
^g|j4N
System.err.println("文件下载结束！"); [_eT{v2B4
} ppo.#p0w
catch(Exception e){e.printStackTrace ();} %+htA0aX
} -{}(U
]=o1to-
L+mE&
//获得文件长度 Lv?jg?$
public long getFileSize() YqmsL<
{ We++DWp
int nFileLength = -1; xw}rFY$
try{ blLl1Ak
URL url = new URL(siteInfoBean.getSSiteURL()); +DG-MM%\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `_f&T}]
httpConnection.setRequestProperty("User-Agent","NetFox"); &q&~&j'[
MDQ:6Ri
#zv&h`gY
int responseCode=httpConnection.getResponseCode(); h3bQ<?m
if(responseCode>=400) 7H*,HZc@=
{ Q;N)$Xx
processErrorCode(responseCode); /6rQ.+|).
return -2; //-2 represent access is error h<V,0sZ&:
} o|u4C{j
'qUM38s
9M^5<8:
String sHeader; @~Ys*]4UE
LF`]=.Q
JMk2OK{0
for(int i=1;;i++) 8[.&ca/[
{ QLU <%w:B
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2ql)]Skg6
//Utility.log(in.readLine()); cuC' o\f
sHeader=httpConnection.getHeaderFieldKey(i); );T&pm:C>
if(sHeader!=null) TMD\=8Na
{ <"K2t Tg.
if(sHeader.equals("Content-Length")) n=)LB& m
{ S|xwYaoy%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); pP#D*hiP-g
break; /Xj{]i3{
} e_-7,5Co
} dWi<U4
else *o5[P\'6
break; 7O8 @T-f+2
} $}IG+,L
} $vK,Gugcx
catch(IOException e){e.printStackTrace ();} _X
catch(Exception e){e.printStackTrace ();} .Tm.M7
\03<dUA6
}Ml BmD
Utility.log(nFileLength); \[qxOZ{
%y\5L#T!>
uF|Up]Z G
return nFileLength; AFM+`{Cq
} "uP*pR^
}z#M!~
C:t?HLY)fG
//保存下载信息（文件指针位置） *|j4>W\J
private void write_nPos() w#hg_RK(Jr
{ k]C k%[d
try{ KgbBa2@+
output = new DataOutputStream(new FileOutputStream(tmpFile)); RT3(utwO
output.writeInt(nStartPos.length); R:(i}g<3
for(int i=0;i<nStartPos.length;i++) .N>*+U>>P
{ P3YM4&6XA
// output.writeLong(nPos); S>b 3_D
output.writeLong(fileSplitterFetch.nStartPos); |QF_E4ISD
output.writeLong(fileSplitterFetch.nEndPos); q"@#FS
} }A]eC
output.close(); R!%HQA1U
} j/Y]3RSMp
catch(IOException e){e.printStackTrace ();} WVsj
catch(Exception e){e.printStackTrace ();} =L@CZ"
} AbhR*
{qlcTc
IA&V?{OE@I
//读取保存的下载信息（文件指针位置） b%*`}B
private void read_nPos() /P-#y@I
{ 9D &vxKE
try{ T{^P
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); r73W.&
int nCount = input.readInt(); l*]hUPJ
nStartPos = new long[nCount]; .gGO+8[N*
nEndPos = new long[nCount]; 7QnWw0
for(int i=0;i<nStartPos.length;i++) mA$86X_
{ 1=5HQ~|[TO
nStartPos = input.readLong(); [mQ1r*[j
nEndPos = input.readLong(); si)>:e
} Nd"IW${Kg
input.close(); m&b1H9ymd
} h_ccE6]t
catch(IOException e){e.printStackTrace ();} "f<gZsb
catch(Exception e){e.printStackTrace ();} R2?s NlF
} )iiaT~ ]
5M~+F"Hl
,?Ie!r$6
private void processErrorCode(int nErrorCode) Z*f%R\u
{ bcvm]aPu
System.err.println("Error Code : " + nErrorCode); ItvcN
} _68vSYr
XkkzY5rxOc
!;mn]wR>a
//停止文件下载 iLJ@oM;2
public void siteStop() yGNpx3H
{ ^n<YO=|u
bStop = true; U^|T{g+O
for(int i=0;i<nStartPos.length;i++) U}DE9e{/!
fileSplitterFetch.splitterStop(); %FM26^
fMUh\u3
#"~\/sb
} @k)J i!7
} YmFg#eS
//负责部分文件的抓取 t:V._@
**FileSplitterFetch.java 0G-obHe0
*/ 9G2rVk
package NetFox; [zm@hxym
kaQNcMcq
uF|_6~g
import java.io.*; i/n ee_
import java.net.*; DBsoa0w
ZO/Jf Jn~
_q1\8y
public class FileSplitterFetch extends Thread { Ipq0 1 +
)`{m |\b
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String sURL; //File URL $0K@=7ms
long nStartPos; //File Snippet Start Position %XeN_ V
long nEndPos; //File Snippet End Position <uS/8MP{
int nThreadID; //Thread's ID 3Mm_xYDud
boolean bDownOver = false; //Downing is over P(Rl/eyRM
boolean bStop = false; //Stop identical W|Sab$h
FileAccessI fileAccessI = null; //File Access interface Iox)-
b/qK/O8J
vdvnwzp!l
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s@iY'11
{ l1lYb;C
this.sURL = sURL; Z2yO /$<
this.nStartPos = nStart; Cw(ypu
this.nEndPos = nEnd; D@9 +yu=S
nThreadID = id; QD{1?aY
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4U}J?EB?K
} (0#$%US\
F(."nUrf
I<sUB4T>#W
public void run() lb}RPvQE
{ fap]`P~#L
while(nStartPos < nEndPos && !bStop) IAGY-+8e
{ mF~]P8
<z2.A/L
2[3t7C
try{ QtG6v<A
URL url = new URL(sURL); ps:`rVQ7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 13Z,;YW
httpConnection.setRequestProperty("User-Agent","NetFox"); _*?qOmf=
String sProperty = "bytes="+nStartPos+"-"; O9d"Z$~n=j
httpConnection.setRequestProperty("RANGE",sProperty); <`=Kt[_BQ
Utility.log(sProperty); P2f^]z
UCmy$aW
-Z:x!M[Xr
InputStream input = httpConnection.getInputStream(); vX6JjE!
//logResponseHead(httpConnection); &PL=nI\)
LFxk.-{=
+%,oq]<[,
byte[] b = new byte[1024]; LI3L~6A>
int nRead; F.aG7
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) N0^SWA|S
{ jlF3LK)9q
nStartPos += fileAccessI.write(b,0,nRead); +aEm]=3
//if(nThreadID == 1) $ -<(geI
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9M7P|Q
} #yR&|*@
MG.c`t/w
l#T%N@X
Utility.log("Thread " + nThreadID + " is over!"); ~' 955fK>
bDownOver = true; _+aR|AEC
//nPos = fileAccessI.write (b,0,nRead); '{.4~:
} X>uLGr>
catch(Exception e){e.printStackTrace ();} sCY
} 7bO>[RQB
} gI2'[OU
yv]|Ce@8A
cMT:Ij];
//打印回应的头信息 MK/8<i<.
public void logResponseHead(HttpURLConnection con) tF-l=ph}`
{ A'~mJO/
for(int i=1;;i++) 8]vut{
{ !LpjTMYs
String header=con.getHeaderFieldKey(i); F."ZCEb
if(header!=null) e4Qjx*[G
//responseHeaders.put(header,httpConnection.getHeaderField(header)); PPySOkmS3
Utility.log(header+" : "+con.getHeaderField(header)); T6\]*mlr
else _6c/,a8;*J
break; B@ufrQ#Y.
} z a_0-G%C2
} Tq)hAZ
\}.bTca
W$,/hB& z
public void splitterStop() `W+-0F@Y?@
{ bfncO[Q,?
bStop = true; `S-l.zSZ4B
} hg0{x/Dgny
d`flYNg4
TW(X#T@Z6I
} { ?jXPf
]R}(CaT1
4[kyzz x
/* N;-%:nC
**FileAccess.java BxV>s+o&]
*//文件访问(定位，写) u ynudO
package NetFox; n CX{tqy
import java.io.*; eXnSH$uI
wN%lc3[/z2
(G./P@/[
public class FileAccessI implements Serializable{ 6S{F4v2/0
Uvc$&j^k
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 t}Td$K7
RandomAccessFile oSavedFile; z?Z"*z
long nPos; d(^HO~p
6A.%)whI;
%vZHHBylu
public FileAccessI() throws IOException Pvt!G
{ &v;fK$=2C
this("",0); .s4v*bng
} V0 Z8VqV
pT~3< ,
:8/ 6dx@Y(
public FileAccessI(String sName,long nPos) throws IOException #*y.C[^5{
{ 7 qn=W
oSavedFile = new RandomAccessFile(sName,"rw"); e>c -b^{&
this.nPos = nPos; }{@y]DcdM4
oSavedFile.seek(nPos); ^;s/4
} 3`{ vx
rloxM~7!,)
j<BRaT
public synchronized int write(byte[] b,int nStart,int nLen) jz=V*p}6
{ y*sVimx
int n = -1; pnp8`\cIH
try{ p&<n_b
oSavedFile.write(b,nStart,nLen); CC3i@
n = nLen; D8~\*0->
} )h0>e9z>Y
catch(IOException e) z<fd!g+^
{ [$d]U.
e.printStackTrace (); d&|5Rk ~
} 4 Cd5-I
9__Q-J
p8-$MF]]6
return n; K$}K2w
} $?z}yx$
+'93%/:
YG=:lf
} ZWS:-]P.
- uO(qUa#
*6AqRE
/* L..
**SiteInfoBean.java ~J~R.r/
*/ ?F$#t6Q
package NetFox; G;wh).jG5
NCzabl
@@\px66
public class SiteInfoBean { MxX)&327
kiyKL:6D|
#Q["[}flVv
private String sSiteURL; //Site's URL "O$WfpKX
private String sFilePath; //Saved File's Path OIw[sum2
private String sFileName; //Saved File's Name bw/mF5AsW
private int nSplitter; //Count of Splited Downloading File qHyOaKMd
Z{l`X#':
`#!>}/m
public SiteInfoBean() 4:O.x#p
{//nSplitter的缺省值为5 1GkoE
//default value of nSplitter is 5 ft@#[Bkx
this("","","",5); GoX<d{
} .+?]"1>]
_ Dz*%
Ho(}_Q&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) I H#CaD
{ *>[q*SF
sSiteURL= sURL; p-(V2SP/)t
sFilePath = sPath; %qeNC\6N
sFileName = sName; o2$A2L9P
this.nSplitter = nSpiltter; OKau3T]
Y^d#8^cP
+.^pAz U}R
} 4)}>dxv
l]t^MEoc8
l'2vo=IQ
public String getSSiteURL() FGc#_4SiL
{ `S?_=JIX
return sSiteURL; !h}Vz
} L">jSZW[[
jJvd!,=)
D_ej%QtB@
public void setSSiteURL(String value) )`Qr=DIsW
{ uhaHY`w
sSiteURL = value; Ywt9^M|z;
} n|Y}M]u,
G#NbLj`h
v5?)J91
public String getSFilePath() KkzG#'I1
{ zZ51jA9x
return sFilePath; qJl DQc-
} J%q)6&
"9Q_lVI|Q
E;4dlL`*
public void setSFilePath(String value) ${ DSH
{ k'e1ZAn
sFilePath = value; #^|2PFh5
} 8~.8"gQ
|7Z}#eP//
kDQE*o
public String getSFileName() l$HBYA\Qh
{ /']`}*d
return sFileName; ;F%EW`7
} B2_fCSlg
oL>o*/
d%q&[<'jf
public void setSFileName(String value) n^qwE
{ Q=[ IO,f
sFileName = value; HKOSS-`5
} 2t?>0)*m
wXdt\@Qr
D]'8BS3
public int getNSplitter() vt(}8C+
{ XS&;8 PO
return nSplitter; B 'd@ms
} bng/v
/=#~8
&FZ~n?;hQ
public void setNSplitter(int nCount) ) R5[aO
{ &K=)YpT
nSplitter = nCount; ,PKUgL}w
} v-!Spf
} <+%y
1`Bhis9X8
}+u<w{-7/
/* ,ag* /
**Utility.java <5FGL96
*/ CL(D&8v8~
package NetFox; ||7x51-yj
,%V%g!6{
Y|/,*,u+
public class Utility { r`+G9sj3U
=&.9z 4A
PuBE=9,
public Utility() :Us+u-~
{ SD:Bw0gzrI
.K#' Fec
2Mw`
} Ib/e\+H\
z<yqQ[
//线程睡眠 7o*~zDh@fH
public static void sleep(int nSecond) /6x[C
{ PCc{0Rp\vk
try{ D7B g!*
Thread.sleep(nSecond); iM8l,Os]<f
} }^n"t>Z8
catch(Exception e) fP( n3Q
{ =gd~rk9
e.printStackTrace (); k%N$eO$
} Vm I Afe
} ?4W6TSW-'
\vL{f;2J
//日志 !L)|N<
public static void log(String sMsg) _4k zlD
{ vr kj4Jf
System.err.println(sMsg); i~4$V
} (ze9-!%
d:z7 U
6s!=de
public static void log(int sMsg) +J42pSxzoo
{ Ycxv=Et
System.err.println(sMsg); <fgf L9-
} J/Ch /Sa
} |NFDrm
>pq=5Ha&
HMKogGTTo
/* x IL]Y7HWM
**TestMethod.java Qk.[#
*/ 9!Fg1h=
package NetFox; I "R<XX
d=g,s[FMm
!(j<Y0xo:
public class TestMethod { iE ,"YCK
2ryg3%+O
9wC='
public TestMethod() u*7>0o|H:
{ ///xx/weblogic60b2_win.exe i>pUTT _[
try{ mJVru0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "1Y DT-I"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); og*ti!Z
SiteFileFetch fileFetch = new SiteFileFetch(bean); >T\^dHtz
fileFetch.start(); _2}/rwVg
} _znn`_N:v
catch(Exception e){e.printStackTrace ();} i$!K{H1{9
U[ogtfv`m
qvJQbo[.9P
} Y)AHM0;g
gm: xtN
"Z-YZ>2
public static void main(String[] args) axkNy}ct
{ NV2$ >D
new TestMethod(); ;s$ P?('
} G98fBw
} IfCa6g<&(
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