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)); F>cv<l =6l
} @K]|K]cby
for(int i=0;i<nEndPos.length-1;i++) *:NQ&y*uj
{ 8*fv'
nEndPos = nStartPos[i+1]; HKr Mim-
} )WoxMmz
nEndPos[nEndPos.length-1] = nFileLength; .6V}3q$-@
} ^I)N. 5
} e$pV%5=
hzRYec(
g[t [/TV
//启动子线程 * H9 8Du
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; V_:&S2j
for(int i=0;i<nStartPos.length;i++) :hV7> rr
{ )0R'(#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )Beiu*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?rup/4|
nStartPos,nEndPos,i); m9A!D
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Bw{I;rW{2
fileSplitterFetch.start(); ukY"+&
} Bnd [X
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [sb[Z:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); MxGW(p
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", e!r-+.i(
nEndPos = " + nFileLength); AvHCO8h|
// fileSplitterFetch[nPos.length-1].start(); @gtQQxf"
^BL"wk
2>H24F
//等待子线程结束 FEVlZ<PW3I
//int count = 0; Wr5V`sM
//是否结束while循环 {>%&(
boolean breakWhile = false; z"4~P3>{g
BX^tR1
(3&?wy_l
while(!bStop) -)/$M(Pu"
{ h65-s
write_nPos(); -Vhw^T1iV
Utility.sleep(500); uOGw9O-d9
breakWhile = true; ilva,WFa^
-o.:P>/
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for(int i=0;i<nStartPos.length;i++) )];K .zP
{ 5P$4 =z91
if(!fileSplitterFetch.bDownOver) 0P(!j_2m
{ 1>&]R=
breakWhile = false; I)W`sBL
break; ^Va1f'g
} Lu0x (/
} R^e.s -
if(breakWhile) s|B3~Q]
break; t!\tF[9e
XF_pN[}
C{XmVc.
//count++; f>Jr|#k
//if(count>4) K!]/(V(}
// siteStop(); *r% c
} 9RI-Lq`
m<g~H4
{$Gd2gO
System.err.println("文件下载结束！"); c:u5\&~{
} uL/m u<
catch(Exception e){e.printStackTrace ();} Ji 0 tQV
} FjI`uP
,<p}o\6
U!Z,xx[]
//获得文件长度 K:Q<CQ2
public long getFileSize() iRi-cQVy
{ %-e 82J1
int nFileLength = -1; s&!a
try{ '-/xyAzS
URL url = new URL(siteInfoBean.getSSiteURL()); k,F6Tx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xpx\=iAe
httpConnection.setRequestProperty("User-Agent","NetFox"); \K<QmK
a+T.^koY
K>l~SDcZ3
int responseCode=httpConnection.getResponseCode(); qXjxNrK
if(responseCode>=400) Nm>A'bLM
{ LAe6`foW/
processErrorCode(responseCode); 4vV:EF-
return -2; //-2 represent access is error v2;`f+
} ,T8~L#M~
!GEJIefx_
e,XYVWY%
String sHeader; ; p{[1
_W'-+,
\A6B,|@
for(int i=1;;i++) fLm*1S|%\
{ |WdPE@P
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \`\ZTZni
//Utility.log(in.readLine()); B i<Q=x'Z;
sHeader=httpConnection.getHeaderFieldKey(i); DXK}-4"\
if(sHeader!=null) JOim3(5?s
{ Z@@K[$
if(sHeader.equals("Content-Length")) fn6J*[`
{ f[^Aw(o
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 84pFc;<
break; =+MPFhvg!
} -n<pPau2
} Y~E`9
else ; XN{x
break; :7?FF'u
} X=8{$:
} M b1sF
catch(IOException e){e.printStackTrace ();} j;iAD:nf
catch(Exception e){e.printStackTrace ();} ;Nj7qt
!V g`
4J([6<
Utility.log(nFileLength); pDCeQ6?
3+fp2
\1 &,|\E#
return nFileLength; l9u!aD
} FA3~|Zg
EJ:%}HhA
nl,uuc*;
//保存下载信息（文件指针位置） EeRX+BM,
private void write_nPos() c[1oww
{ V0XvJ
try{ 6}Y#=}
output = new DataOutputStream(new FileOutputStream(tmpFile)); O,h;hQZ
output.writeInt(nStartPos.length); :|8M`18lZ
for(int i=0;i<nStartPos.length;i++) {"QNJq#:
{ zY!j:FT1HY
// output.writeLong(nPos); FfPar:PHj
output.writeLong(fileSplitterFetch.nStartPos); k<{{*
output.writeLong(fileSplitterFetch.nEndPos); spPNr
} oVfLnI;
output.close(); &,CiM0
} P8)=Kbd
catch(IOException e){e.printStackTrace ();} ,.1Psz^U
catch(Exception e){e.printStackTrace ();} Y@ksQ_u
} qd)/9*|Jl
Fv<F}h?6
.KUv(-
//读取保存的下载信息（文件指针位置） Z%/=|[9i
private void read_nPos() }YNR"X9*)/
{ NI [ pp`
try{ C-MjJ6D<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); zvH8^1yzG
int nCount = input.readInt(); 2=`o_<P'"
nStartPos = new long[nCount]; l6 H|PR{
nEndPos = new long[nCount]; \(Y\|zC'0$
for(int i=0;i<nStartPos.length;i++) e`xdSi>E
{ mFaZio0GK
nStartPos = input.readLong(); D(RTVef
nEndPos = input.readLong(); c%G{#}^2
} /M4{Wc
input.close(); c>Xs&_
} QY?~ZwYB
catch(IOException e){e.printStackTrace ();} gPsi
catch(Exception e){e.printStackTrace ();} (l-ab2'
} YccH+[X;
H'HA+q
j<@lX^
private void processErrorCode(int nErrorCode) s`'{I8'p/
{ )PuFuf(wz
System.err.println("Error Code : " + nErrorCode); ?>rW>U6:P
} sN2p76KN
&NK,VB;
j4`0hnqI
//停止文件下载 v`zJb00DT
public void siteStop() gSUcx9f]
{ MET' (m
bStop = true; $79=lEn,
for(int i=0;i<nStartPos.length;i++) "4+WZR]
fileSplitterFetch.splitterStop(); 0rDh}<upjk
i/ )am9
giIWGa.a+
} ]d0tE?9
} \$e)*9)
//负责部分文件的抓取 Xudg2t)+K
**FileSplitterFetch.java _p&]|~a
*/ [@b&? b~K
package NetFox; iIa'2+
pDIVZC
u TK,&
import java.io.*; uPG4V2
import java.net.*; 2fR02={-
Md2>3-
khrb-IY@
public class FileSplitterFetch extends Thread { DB:+E|vSD
/.MN
;1.,Sn+zO
String sURL; //File URL _Khc3Jo
long nStartPos; //File Snippet Start Position 87P>IO
long nEndPos; //File Snippet End Position +hT:2TXn
int nThreadID; //Thread's ID )oPLl|=h
boolean bDownOver = false; //Downing is over /bi[e9R
boolean bStop = false; //Stop identical \LppYXz
FileAccessI fileAccessI = null; //File Access interface Q/_f zg
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DhT>']Z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException v` 7RCg`
{ ]0)|7TV*
this.sURL = sURL; O8u j`G 9
this.nStartPos = nStart; -}=%/|\FG
this.nEndPos = nEnd; ,:H\E|XeBw
nThreadID = id; FUOI3
fileAccessI = new FileAccessI(sName,nStartPos);//定位 b6F4>@gjg
} )3w@]5j
&[/w_|b
)Es"LP]
public void run() muZ~*kMc
{ DRgTe&+
while(nStartPos < nEndPos && !bStop) ul2")HL];
{ CS-uNG6
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try{ k |%B?\m
URL url = new URL(sURL); }J1tdko#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F\k+[`%{
httpConnection.setRequestProperty("User-Agent","NetFox"); hn=[1<#^(
String sProperty = "bytes="+nStartPos+"-"; YmgLzGk`
httpConnection.setRequestProperty("RANGE",sProperty); ?5cI'
Utility.log(sProperty); &n?^$LTPY
0[*qY@m:Z
q+]h=:5=I
InputStream input = httpConnection.getInputStream(); ^(h+URFpA
//logResponseHead(httpConnection); TGe;HZ
T{Uc:Z
c|62jY"$-2
byte[] b = new byte[1024]; *2Ht&
int nRead; dJ""XaHqf
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [P7N{l=I
{ &2zq%((r
nStartPos += fileAccessI.write(b,0,nRead); 0B@Jity#!
//if(nThreadID == 1) Qj6/[mUr~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R>"OXFaE
} y+6o{`0
pg%aI,
)>-ibf`#?
Utility.log("Thread " + nThreadID + " is over!"); Zxbq
bDownOver = true; glXZZ=j
//nPos = fileAccessI.write (b,0,nRead); iN0nw]_*
} Yvjc1
catch(Exception e){e.printStackTrace ();} -'BA{#e}L
} $.v5~UGb{\
} $K'|0
UHxE)]J
MR<;i2p
//打印回应的头信息 C[Dav&=^F
public void logResponseHead(HttpURLConnection con) aj,T)oDbt6
{ I=9!Rs(QF
for(int i=1;;i++) z`FCs,?K
{ B0WJ/)rK<
String header=con.getHeaderFieldKey(i); ez!C?
if(header!=null) mAW,?h
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 'n$%Ls}S
Utility.log(header+" : "+con.getHeaderField(header)); ql?=(b;D
else e=;AfK
break; %v7[[U{T
} Zg`Mz _?
} S"k*6U
OP|8Sk6 r
e-*.Ca
public void splitterStop() (B-43!C
{ `8>Py~
bStop = true; 9*=W-v
} |{ PI102
['*8IWg
X'% ;B
} QZhjb
g HbxgeL
njnDW~Snb
/* -7&Gi +]
**FileAccess.java D<X.\})Md
*//文件访问(定位，写) R% ,<\d7
package NetFox; ZwerDkd
import java.io.*; NDAw{[.%
#\ n8M
M7+h(\H]2
public class FileAccessI implements Serializable{ &o97u4xi
,qrQ"r9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 GSQ/NYK
RandomAccessFile oSavedFile; 7ei|XfR
long nPos; 3^~KB'RZ
V{&rQ@{W
`TPOCxM Mo
public FileAccessI() throws IOException m7GR[MR
{ u=/CRjot
this("",0); pOkLb #
} JiU9CeD3
dG71*)<)t
}sFm9j7yR
public FileAccessI(String sName,long nPos) throws IOException P?]aWJ
{ {]]|5 \F
oSavedFile = new RandomAccessFile(sName,"rw"); :C8$Xi_i}
this.nPos = nPos; LtKI3ou
oSavedFile.seek(nPos); FSbHn{@
} )Cw`"n
;kJA'|GX
g@Qgxsyk>
public synchronized int write(byte[] b,int nStart,int nLen) b(I2m
{ PeE/iZ.
int n = -1; 2kUxD8BcN
try{ F5qFYL;
oSavedFile.write(b,nStart,nLen); AkT<2H|4
n = nLen; A &9(mB
} okFvn;
catch(IOException e) T'aec]u
{ l?)ZJ3]a
e.printStackTrace (); H7kPM[
} A?T<",bO
FsGlJ
9A7@ 5F
return n; !!nuAQ"E[
} h<\_XJJ
H<G4O02i_
3o|I[!2.
} ,mL !(US
k%op> &
v^7LctcVm
/* !;!~n`
**SiteInfoBean.java b2b75}_A
*/ +EM_TTf4
package NetFox; Y05P'Q
}/,CbKi,+
on7I l
public class SiteInfoBean { oq_6L\ ~
EIf~dOgH
Q!FLR>8
private String sSiteURL; //Site's URL #s%-INcR
private String sFilePath; //Saved File's Path ?<yM7O,4
private String sFileName; //Saved File's Name WmQ01v
private int nSplitter; //Count of Splited Downloading File )*d W=r/$V
9r2IuS0
$.489x+'Z
public SiteInfoBean() xT)psM'CL
{//nSplitter的缺省值为5 <p?&udqD
//default value of nSplitter is 5 X}6#II
this("","","",5); *$M'`vj:
} V8~jf-\$b
U#o'H @
6R29$D|HFO
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *AIEl"29
{ 9=/N|m8.
sSiteURL= sURL; Bz`yfl2
sFilePath = sPath; )P>u9=?,=E
sFileName = sName; /+3a n9h
this.nSplitter = nSpiltter; N6[i{;K@N{
Gj /3kS~@
jUqy8q&
} 6dEyv99
PZD>U)M
rB%$;<`/
public String getSSiteURL() #9LzY
{ ksjUr1o
return sSiteURL; jAsO8
} \ U-vI:J_
il:nXpM!
@oG)LT
public void setSSiteURL(String value) ~H}en6Rc
{ qUF1XJZ}z
sSiteURL = value; 0X(]7b&~R
} J:F^ #gW
BXUF^Hj%
efuK
public String getSFilePath() kDz>r#%
{ wn11\j&
return sFilePath; 2PSTGG8JV
} n|4;Hn1V
hD<f3_k
XL}<1-}
public void setSFilePath(String value) L6i|:D32p
{ %E27.$E_
sFilePath = value; ".~{:=
} uC]Z8&+obb
7=*VpX1
[Id}4[={e
public String getSFileName() IGAzE(
{ 4o9$bv
return sFileName; I2HT2c$
} qU[O1bN
}o9Aa0$*$
]9S`[c$
public void setSFileName(String value) S C_|A9
{ RwTzz] M
sFileName = value; X^@[G8v%
} BZF,=v
}1%r%TikY
|[cdri^?D
public int getNSplitter() I&1!v8
{ C/v}^#cLD
return nSplitter; |&hU=J o
} 0D)`2W
Z]-WFU_ N
s!6=|SS7
public void setNSplitter(int nCount) p#_[
{ `!w^0kZ
nSplitter = nCount; 8t.dPy<
} N)43};e
} =V^@%YIn
i|\{\d
a]VGUW-
/* $<ddy/4
**Utility.java GF--riyfB
*/ iY.eJlfH
package NetFox; KC&`x|
+|C[-W7Sw
:J(sXKr[C
public class Utility { @PcCiGZ
nJVp.*S
{(vOt'
public Utility() ,{j4
{ +*t|yKO>[
TV{)n'aA
t^@T`2jL
} c#q"\"
6d{j0?mM
//线程睡眠 ?TuI:dC
public static void sleep(int nSecond) "]]q} O?
{ d]M[C[TOX
try{ 2X@G"
Thread.sleep(nSecond); } 21j
} .u< U:*
catch(Exception e) K~>jApZ%
{ ~5t?C<wo
e.printStackTrace (); xtJAMo>g
} _IYY08&(r
} t>U!Zal"
gEKO128
//日志 X7e/:._SAH
public static void log(String sMsg) sA_X<>vAKJ
{ /Antb6E
System.err.println(sMsg); .k]#XoE
} z/vDgH!s
org*z!;.
r69WD .
public static void log(int sMsg) cTj~lO6
{ V<$*Y>;
System.err.println(sMsg); POBpJg
} _ +KmNfR
} RWahsJTu
B/Ba5z"r$
#Si|!
/* 3Hm7 uBZ
**TestMethod.java caD5Pod4
*/ ,35Ag#va
package NetFox; deM~[1e[
~N[|bPRmhE
3zb)"\(R
public class TestMethod { ma7fDo0,`h
<R~KM=rL
Cj$H[K}>
public TestMethod() d[U1.SNL
{ ///xx/weblogic60b2_win.exe 5<r)+?!n
try{ apaIJ+^[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); WOH9%xv
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {U P_i2`.
SiteFileFetch fileFetch = new SiteFileFetch(bean); oYqE*mA
fileFetch.start(); \G=bj;&eF
} ' PL_~
catch(Exception e){e.printStackTrace ();} s?<!&Y
3*\8p6G
i;HH ! TaN
} V~c(]K)-
Isp_U5M
u-M] Az-
public static void main(String[] args) Fc{((x s
{ h*l4Y!7
new TestMethod(); TA9dkYlE/
} T`mEO\f
} Dtt\~m;AR
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