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)); :8yebOs
} IdmP!(u
for(int i=0;i<nEndPos.length-1;i++) rJiF2W
{ @76}d
nEndPos = nStartPos[i+1]; E@ea?Sx
} #2]*qgA4
nEndPos[nEndPos.length-1] = nFileLength; SeHrj&5U
} S{^x]h|?
} 72l:[5ccR
}a"=K%b<\
A$2 ;Bf
//启动子线程 7$*E0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Tvv>9gS
for(int i=0;i<nStartPos.length;i++) r_+Vb*|Y
{ SdnnXEB7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )Jt. Z^J<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), mm>l:M TF
nStartPos,nEndPos,i); GCl *x:
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WJ8i=MO67
fileSplitterFetch.start(); $%EX~$=m]-
} h0F=5| B
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @Ou H=<YN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Cu@q*:'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", & AK\Pw)
nEndPos = " + nFileLength); ]!ai?z%cK#
// fileSplitterFetch[nPos.length-1].start(); .@{v{
h1~h&F?
S)hDsf.I
//等待子线程结束 g4+K"Q/M
//int count = 0; An_(L*Qz
//是否结束while循环 "](Q2
boolean breakWhile = false; wR_mJMk_
3EYEd39E
z</C)ObL
while(!bStop) f0P,j~]
{ JSUD$|RiJ
write_nPos(); 2TGND-(j
Utility.sleep(500); -;cF)C--12
breakWhile = true; 0MRWx%CR
vjX,7NY?
P5my]4|x
for(int i=0;i<nStartPos.length;i++) #M!u';bZ
{ %oiF} >
if(!fileSplitterFetch.bDownOver) gdIk%m4
{ /Xi21W/
breakWhile = false; 0(i3RPIj\
break; _i>_Sn1"
} `,4yGgD!4
} )M;~j
if(breakWhile) 0er|QC
break; SY Bp-o
t,YRM$P
K~#?Y,}O
//count++; e6p3!)@P1
//if(count>4) M4Cb(QAVP
// siteStop(); I'xc$f_+
} (?Ko:0+*
Ucv7`W gr
hTa X@=Ra
System.err.println("文件下载结束！"); P4B|l:
} i6yA>#^
catch(Exception e){e.printStackTrace ();} A{>w5T
} '/`O*KD]
@vq)Y2)r\
cn}15JHdR
//获得文件长度 Q m*z
public long getFileSize() ^?{&v19m
{ DOu^
int nFileLength = -1; igL5nE=n
try{ 9Qszr=C0
URL url = new URL(siteInfoBean.getSSiteURL()); +788aK,{#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =w`Mc\o"
httpConnection.setRequestProperty("User-Agent","NetFox"); 6W_:w
|6^a[x3/U
Xr^ 5Th\
int responseCode=httpConnection.getResponseCode(); 2|7:`e~h
if(responseCode>=400) {ccc[G?>.Q
{ |8E~C~d
processErrorCode(responseCode); r.)n>
return -2; //-2 represent access is error yLf9cS6=
} TeuZVy8a
z?13~e[D
dWzf C@]
String sHeader; @~vg=(ic(
R:n|1]*f3X
bbq`gEV
for(int i=1;;i++) OybmyGHY
{ e!0xh
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2MB>NM<xO
//Utility.log(in.readLine()); x#E M)Thq
sHeader=httpConnection.getHeaderFieldKey(i); Q"s6HZ"YI
if(sHeader!=null) W/A@qo"
{ V=fu[#<@Ig
if(sHeader.equals("Content-Length")) #}fvjJ{
{ @|;[ ;:h@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +o3n%( ^~
break; ]*]*O|w
} ;Qy Ew5
} G[e,7jev
else 8;`B3N7
break; lI46 f
} FS8l}t
} <VU-ja*(J
catch(IOException e){e.printStackTrace ();} =oXlJ[)h
catch(Exception e){e.printStackTrace ();} POm;lM$
-J!n7
S7J.(; 82
Utility.log(nFileLength); 4 dHGU^#WZ
:*g$@T
?r=`Kl
return nFileLength; t,TlW^-
} g_ep 5#\D
gLSI?
_"F=4`lJ
//保存下载信息（文件指针位置） 8~qpOQX^V
private void write_nPos() 3<.DiY
{ 6Jy%4]wK
try{ A'![*O
output = new DataOutputStream(new FileOutputStream(tmpFile)); Jv 5l
output.writeInt(nStartPos.length); aPe*@py3T
for(int i=0;i<nStartPos.length;i++) O:+y/c
{ Uf_mwEE
// output.writeLong(nPos); 7#"y mE
output.writeLong(fileSplitterFetch.nStartPos); I;AS.y
output.writeLong(fileSplitterFetch.nEndPos); ^x*J4jl
} ~BTm6*'h
output.close(); sAO/yG
} 9FC_B+7
catch(IOException e){e.printStackTrace ();} ?!F<xi:
catch(Exception e){e.printStackTrace ();} +?t& 7={~
} zxs)o}8icO
*fd:(dN|
?r]0%W^
//读取保存的下载信息（文件指针位置） "=%YyH~WY
private void read_nPos() _@?I)4n|
{ IecD41%
try{ 8WLh7[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); PRYm1Y
int nCount = input.readInt(); Gyy4)dP
nStartPos = new long[nCount]; 3#""`]9H
nEndPos = new long[nCount]; `6Q+N=k~Z
for(int i=0;i<nStartPos.length;i++) Ts, U T L
{ 0n X5Vo
nStartPos = input.readLong(); s(5(zcBK
nEndPos = input.readLong(); ?N+pWdi
} _ZWU~38PM
input.close(); 6V9r[,n
} IY~I=}
catch(IOException e){e.printStackTrace ();} }|-8-;
catch(Exception e){e.printStackTrace ();} B~Z61
} 3>5gh8!-
9]chv>dO)=
@w%kOX
private void processErrorCode(int nErrorCode) \Rt>U|%
{ tOF8v8Hd
System.err.println("Error Code : " + nErrorCode); kSJ;kz,_
} "a _S7K
@G=:@;
W }Ll)7(|T
//停止文件下载 [N*S5^>1
public void siteStop() OvC@E]/+
{ @VND}{j
bStop = true; 1*#hIuoj'
for(int i=0;i<nStartPos.length;i++) nRHlHu
fileSplitterFetch.splitterStop(); &f A1kG%
u,@ac[!vP
va(6?"9
} }f{5-iwD}
} 4*n1Xu7^x
//负责部分文件的抓取 B'B0e`
**FileSplitterFetch.java >)[W7h
*/ 3<Z@!ft8
package NetFox; 0aGauG[
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z{NK(oW
import java.io.*; _M>S=3w
import java.net.*; cy8r}wD
Q^Vch(`&P
2nFr?Y3g,
public class FileSplitterFetch extends Thread { (Q&jp!WU
bLggh]Fh
Mu" vj*F
String sURL; //File URL <X5V]f
long nStartPos; //File Snippet Start Position _s=<Y^l%x
long nEndPos; //File Snippet End Position /K,@{__JP
int nThreadID; //Thread's ID |e+r~).4B
boolean bDownOver = false; //Downing is over su60j^e*
boolean bStop = false; //Stop identical EcR[b@YI
FileAccessI fileAccessI = null; //File Access interface ;8]Hw a1!
vl`St$$|
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *=%`f=
{ .(Z^[C}
this.sURL = sURL; bL:+(/:
this.nStartPos = nStart; d.>O`.Mu)}
this.nEndPos = nEnd; )C$Ij9<A
nThreadID = id; Py9:(fdS
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m KKa0"
} -&y&b-
N>j*{]OY+{
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public void run() s,laJf
{ Q."rE"}<
while(nStartPos < nEndPos && !bStop) d)%l-jj9,
{ Me+)2S 9
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try{ MA 6uJT
URL url = new URL(sURL); {!4ZRNy(k
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hz2f7g
httpConnection.setRequestProperty("User-Agent","NetFox"); 4l{La}Aj
String sProperty = "bytes="+nStartPos+"-"; dKPx3Y'
httpConnection.setRequestProperty("RANGE",sProperty); :'!_PN
Utility.log(sProperty); p|r>tBv?x
`Z`o[]%
PB:r+[91
InputStream input = httpConnection.getInputStream(); p:!FB8
//logResponseHead(httpConnection); (/P-9<"U
MA mjoH
V2 }.X+u&<
byte[] b = new byte[1024]; &9n=!S'Md
int nRead; ;[,#VtD
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) h9%.tGx
{ ~c=*Y=)LG
nStartPos += fileAccessI.write(b,0,nRead); :r_/mzR#
//if(nThreadID == 1) rN~V^k
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U`4t4CHA
} Bo*Wm w
w 3L+7V,!
$yZP"AsAR
Utility.log("Thread " + nThreadID + " is over!"); QSo48OFs
bDownOver = true; [!#;QQ&M
//nPos = fileAccessI.write (b,0,nRead); U,`F2yD/!
} KXo[;Db)k
catch(Exception e){e.printStackTrace ();} {*Qx^e`h$.
} 6A} 45
} y|#Fu
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z)FGbX
//打印回应的头信息 1Dm$:),^T}
public void logResponseHead(HttpURLConnection con) rIj B{X{Z
{ ({t6Cbw
for(int i=1;;i++) a3_pF~Qx
{ L<N=,~
String header=con.getHeaderFieldKey(i); oPA m*
if(header!=null) <*4r6UFR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gn${@y?
Utility.log(header+" : "+con.getHeaderField(header)); lHgmljn5u
else `[4{]jX+<
break; z0tm3ovp
} ,HW[l.v
} sCAWrbOe>
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OWHHN<
public void splitterStop() UZW)%
{ OmECvL'Z
bStop = true; n\4sNoFI
} xNxSgvco,
H[iR8<rhQ
KQrG|<J
} !*-|s}e
Jpo(O>\P
NFb<fD[C
/* WNV}@
**FileAccess.java 0a's[>-'A
*//文件访问(定位，写) Dn.%+im-u
package NetFox; Y X{F$BM
import java.io.*; =&?BPhJE
hQbz}x
y)+lU
public class FileAccessI implements Serializable{ -IG@v0_w
H*EN199
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 c0:`+>p2
RandomAccessFile oSavedFile; m3Rss~l
long nPos; D3;#:
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mp>Ne6\Tu
public FileAccessI() throws IOException ,A!0:+
{ p+1kU1F0
this("",0); Sa$-Yf
} Eg#WR&Uq"
ksli-Px
^/$bd4,z
public FileAccessI(String sName,long nPos) throws IOException kt hy9<!$
{ m2PI^?|e
oSavedFile = new RandomAccessFile(sName,"rw"); `9p;LZC1K
this.nPos = nPos; 1ihdH1rg[
oSavedFile.seek(nPos); [-JU(:Rh
} zM|Y X<
C.9l${QU
ABnJ{$=n#
public synchronized int write(byte[] b,int nStart,int nLen) _{YUWV50}
{ Vqxxm&^P
int n = -1; GUqBnRA8j
try{ :^992]EBEj
oSavedFile.write(b,nStart,nLen); GA"zO,
n = nLen; F]KAnEf
} lH1gWe
catch(IOException e) _air'XQ&!
{ 7,EdJ[CR$
e.printStackTrace (); /~;om\7r
} D1f}g
w|8T6W|w
ORo,.#<
return n; (<xl _L:*.
} xr1,D5
TKZ[H$Z
W(,3j{d2i
} _T.k/a
5}"9)LT@@w
c^EU&q{4
/* K0]42K
**SiteInfoBean.java Q}:#Hz?U
*/ ,LVZ
package NetFox; #>dj!33
FkY <I]F
X_2pC|C
public class SiteInfoBean { ) i=.x+Q
f#b;s<G
MON]rj7
private String sSiteURL; //Site's URL *'hJ5{U
private String sFilePath; //Saved File's Path 6~c:FsZ)
private String sFileName; //Saved File's Name :[.**,0R
private int nSplitter; //Count of Splited Downloading File 'yR)z\)
BDz7$k]
jdAjCy;s!
public SiteInfoBean() BXB ZX@jVk
{//nSplitter的缺省值为5 7Nt6}${=z
//default value of nSplitter is 5 [e;c)XS[
this("","","",5); cMp#_\B
} EK$3T5e
8zzY;3^h;
`(o:;<&3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -]kvM
{ ;HoBLxb P
sSiteURL= sURL; h3t);}Y}D9
sFilePath = sPath; 5v,_ Hgh
sFileName = sName; R-J^%4U`7
this.nSplitter = nSpiltter; 6>&h9@
#l#8-m8g)
K:(E"d;
} $bsD'Io
+Un(VTD
QSSA)
public String getSSiteURL() T?HW=v_a
{ }YCpd)@
return sSiteURL; 0<#>LWaM_
} =C 7WQ
LeaJ).Maw
FDCc?>,o
public void setSSiteURL(String value) On-zbE
{ `R6dnbH
sSiteURL = value; R]<N";-
} jiqE^j3;
!N'HL-oT
sFV&e->AN\
public String getSFilePath() xTg=oq
{ N`et]'_A}
return sFilePath; 5L\&"['
} "kd)dy95H
=bJ7!&
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public void setSFilePath(String value) x7ZaI{
{ yXT8:2M
sFilePath = value; Ra/Pk G-7
} T:I34E[
7]H<ou
cB=ExD.Q
public String getSFileName() w;;9YFBdM
{ ,=V9?
return sFileName; <NXJ&xs-+
} {ep(_1
Gy)2
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public void setSFileName(String value) yc+pNC)ue_
{ ! G3Gr
sFileName = value; AW8*bq1
} B;e (5y-
03H0(ku=
y4)iL?!J~
public int getNSplitter() M>[e1y>7
{ Hg5:>?Lw@
return nSplitter; +h08uo5c
} LS]0p#
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#f<3[BLx
public void setNSplitter(int nCount) S`8Iu[Ma
{ 76cLf~|d~
nSplitter = nCount; );;UA6CD
} T:Nc^QP|tm
} z3I |jy1
.tcdqL-'
nO+R>8,Q
/* Jb*E6-9G
**Utility.java v=d16
*/ VYjt/\Z
package NetFox; Xz`0nU
"S H=|5+
nvQTJ4,,
public class Utility { h8dFW"cpC
8qL.L(=\/
Swr4De_5
public Utility() QQJf;p7
{ -}3nIk<N
Vh{(*p
}i{A4f`
} TJCE6QG
l];/,J^
//线程睡眠 6n^@Ps
public static void sleep(int nSecond) RdBIbm
{ "+E\os72|
try{ _iL?kf
Thread.sleep(nSecond); -Xx4:S
} ?4^ 0xGyE
catch(Exception e) V503
{ Y (pUd3y
e.printStackTrace (); T+e*'<!O
} .cm2L,1h
} ocu,qL)W
[ ou$*
//日志 ?lML+
public static void log(String sMsg) .,20_<j%=
{ #q4uS~
System.err.println(sMsg); df!i}L
} ^t:dcY7
2RQ-L
PV:J>!]
public static void log(int sMsg) >n^780S|
{ T*nP-b
System.err.println(sMsg); A=3L_ #nO
} :bm%f%gg
} vA}_x7}n(
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mRa\ wEg%
/* 0<O()NMv
**TestMethod.java )2_[Ww|.
*/ -n8d#Qm)
package NetFox; 9:P]{}
W.NZ%~|+e/
<{GVA0nr
public class TestMethod { uFhaN\S
A; wT`c
UWidT+'Sa
public TestMethod() J ZkQ/vp(
{ ///xx/weblogic60b2_win.exe Ptf(p`
try{ a>x6n3{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /ywP 0
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); e[16 7uU
SiteFileFetch fileFetch = new SiteFileFetch(bean); vd)zvI
fileFetch.start(); Q;J( 5;
} ?xrOhA9
catch(Exception e){e.printStackTrace ();} 7B)1U_L0H
d$jwh(Ivs
}opw_h+/F
} Ulx]4;uzf
fbU3-L?
> K?OsvX
public static void main(String[] args) [}]yJ+)
{ rlD!%gG2x
new TestMethod(); *= ?|n
} 15hqoo9!
} a{.q/Tbt
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