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)); !K8Kw W|X
} wD\viuq0
for(int i=0;i<nEndPos.length-1;i++) g"Tb\
{ `hl8j\HV<}
nEndPos = nStartPos[i+1]; kqH:H~sgD
} eh39"s
nEndPos[nEndPos.length-1] = nFileLength; 0.aIcc
} ]\C wa9
} Sl;[9l2
2 rFjYx8D!
] 6X;&=H
//启动子线程 t/wo G9N
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; qkM)zOZ^
for(int i=0;i<nStartPos.length;i++) g@O H,h/
{ E0*KKo%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q4EOI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :`>$B?x+
nStartPos,nEndPos,i); k-Z:z?M
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gkM Q=;Nn
fileSplitterFetch.start(); $} @gR] Z
} :R{pV7<O
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kR+7JUq]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 68?>#o865
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +SB>>
nEndPos = " + nFileLength); :R-_EY$k6
// fileSplitterFetch[nPos.length-1].start(); Q}: $F{
qs%UJ0tR
+n%d,Pz
//等待子线程结束 k-N}tk/5
//int count = 0; y;if+
//是否结束while循环 IAHQT<]
boolean breakWhile = false; Hl#?#A5
d=p=eUd2
Nz77" kC
while(!bStop) E!9(6G4
{ )H>?K0I
write_nPos(); ~n~j2OE
Utility.sleep(500); n *EGOS
breakWhile = true; !(F?Np Am
[v+5|twxpU
iG ,z3/~v
for(int i=0;i<nStartPos.length;i++) w:pPd;nz0Y
{ 6U0BP
if(!fileSplitterFetch.bDownOver) A+MG?k>yg
{ -q]5@s/
breakWhile = false; <t&Qa~mA
break; Dv*d$
} zIA)se Js
} 3L CT-rp
if(breakWhile) *iN5/w{VG
break; | .gE9'"bv
``-pjD(t
\ iA'^69
//count++; A"O\u=!
//if(count>4) K))P 2ss
// siteStop(); mKqXB\<
} DbSR(:
VRZqY7j}g
95E#
System.err.println("文件下载结束！"); Ne)3@?
} 2 :4o`o
catch(Exception e){e.printStackTrace ();} o%,?v 9
} y`i?Qo3
M>Q3;s
vGnFX0?h
//获得文件长度 25Ro )5
public long getFileSize() kWacc&*|
{ bzr QQQ
int nFileLength = -1; ]8htL#C
try{ kTcW=AXu
URL url = new URL(siteInfoBean.getSSiteURL()); lWn}afI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6V"uovN2
httpConnection.setRequestProperty("User-Agent","NetFox"); T/.UMw
XtQwLH+F
"D'rsEh
int responseCode=httpConnection.getResponseCode(); ~.4y* &
if(responseCode>=400) EOZ 6F-':
{ ~Zn|(
processErrorCode(responseCode); ify48]
return -2; //-2 represent access is error }[=)sb_
} ULhXyItL
B]NcY&A
9q+W>wt
String sHeader; ${rWDZ0Z
k 1a?yH)=
*8_Dn}u?Jx
for(int i=1;;i++) 2+/r~LwbK
{ )Ii`/I^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @^<&LG5^
//Utility.log(in.readLine()); C}|.z
sHeader=httpConnection.getHeaderFieldKey(i); %{7*o5`
if(sHeader!=null) ~ MsHV%
{ 3 l}9'j
if(sHeader.equals("Content-Length")) cs7^#/3<
{ lQiw8qD
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &Z3%UOY
break; 8f1M6GK?
} Y<jX[ET!
} =''WA:,=h
else ^<Gxip
break; A|4om=MO
} 3AglvGK7{
} #jzF6j%G
catch(IOException e){e.printStackTrace ();} -L4G)%L\
catch(Exception e){e.printStackTrace ();} HI{h>g T
~]#-S20
<Y6zJ#BD
Utility.log(nFileLength); }& W=
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4JU2x
return nFileLength; z]SEPYq:
} :?j=MV
:nR80]
@/?i|!6
//保存下载信息（文件指针位置） b`$qKO
private void write_nPos() B'Jf&v
{ {* :^K\-
try{ SSCs96
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0g6sGz=
output.writeInt(nStartPos.length); OjAdY\ ]1
for(int i=0;i<nStartPos.length;i++) 2@lGY_O!m
{ !*L)v
// output.writeLong(nPos); $U.|
output.writeLong(fileSplitterFetch.nStartPos); w;{Q)_A
output.writeLong(fileSplitterFetch.nEndPos); + kT ]qH
} pdR\Ne0P*
output.close(); G[JWG
} W!R0:-
catch(IOException e){e.printStackTrace ();} :<bhQY
catch(Exception e){e.printStackTrace ();} |O6/p7+.
} KO7&dM
N*hV/"joZ
7G^Q2w
//读取保存的下载信息（文件指针位置） FNuE-_
private void read_nPos() y2#"\5dC
{ M]p-<R\
try{ k7Qs#L
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (_!I2"Q*
int nCount = input.readInt(); vb?.`B_>&
nStartPos = new long[nCount]; {aq)Y>o5:T
nEndPos = new long[nCount]; ~c<8;,cjYR
for(int i=0;i<nStartPos.length;i++) S5u$I
{ cfilH"EK
nStartPos = input.readLong(); :hs~;vn)
nEndPos = input.readLong(); U]gUGD!5x
} mv#hy
input.close(); Z1I.f"XY
} 37kVJQcA1
catch(IOException e){e.printStackTrace ();} wggB^ }~
catch(Exception e){e.printStackTrace ();} 6pSTw\/6
} 49M1^nMvoo
[T,^l#S1
I<CrEL<5}~
private void processErrorCode(int nErrorCode) qPD(D{,f$
{ qbD 7\%
System.err.println("Error Code : " + nErrorCode); yyljyE
} A.("jb@I
YC8IwyL'
q`/J2r+O
//停止文件下载 W>i%sHH6
public void siteStop() zG<<MR/<
{ tuIZYp8tIN
bStop = true; ,pI9=e@O/z
for(int i=0;i<nStartPos.length;i++) ohqThl
fileSplitterFetch.splitterStop(); $l"%o9ICG
=?0v,;F9|
!L9OJ1F
} s5{=lP
} l*z%Jw
//负责部分文件的抓取 |u?VlRt
**FileSplitterFetch.java " (O3B
*/ )dX(0E4Td/
package NetFox; ,3 /o7'
Sx QA*}N
RG'76?z
import java.io.*; {R-o8N
import java.net.*; Nj3iZD|
6 h#U,G
{eI'0==
public class FileSplitterFetch extends Thread { t4#gW$+^?H
r!dWI
QK+,63@D\=
String sURL; //File URL KzO"$+M
long nStartPos; //File Snippet Start Position ap )B%9
long nEndPos; //File Snippet End Position Uzzm2OS`
int nThreadID; //Thread's ID s$>n U
boolean bDownOver = false; //Downing is over <^Vj1s
boolean bStop = false; //Stop identical F/BR#J1
FileAccessI fileAccessI = null; //File Access interface '7el`Ff
jw=PeT|
GnW MI1$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "}qs+
{ aH{)|?
this.sURL = sURL; ltgtD k
this.nStartPos = nStart; J??AU0vh
this.nEndPos = nEnd; lP`BKc,
nThreadID = id; \alV #>J5
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]}N01yw|s
} F""9O6u
$~.YB\3
}q@#M8b
public void run() i,*m(C@F}
{ 9;U?_
while(nStartPos < nEndPos && !bStop) t kj
{ H( i
dREY m}1
3r kcIVO
try{ `"&Nw,C
URL url = new URL(sURL); A_oZSUrR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $xZ ~bE9
httpConnection.setRequestProperty("User-Agent","NetFox"); Pn OWQ8=
String sProperty = "bytes="+nStartPos+"-"; `L`+`B
httpConnection.setRequestProperty("RANGE",sProperty); &;d N:F;
Utility.log(sProperty); K-C,n~-
WV$CZgL
{IV%_y?
InputStream input = httpConnection.getInputStream(); \6&Ml]1
//logResponseHead(httpConnection); `9K5 ;]
h9ScN(|0y
<Pt?N2]A|
byte[] b = new byte[1024]; Blzvn19'h
int nRead; I61S0lz/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) vlbZ5
{ E^F<"mL*
nStartPos += fileAccessI.write(b,0,nRead); 50N4J
//if(nThreadID == 1) YkWHI(p
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h7"U1'b
} $q@d.Z>;
43AzNXWF8
"g"a-{8
Utility.log("Thread " + nThreadID + " is over!"); ,sAAV%">
bDownOver = true; @Uez2?
//nPos = fileAccessI.write (b,0,nRead); TsaQR2J@
} 3MQZ)!6
catch(Exception e){e.printStackTrace ();} )Wk_|zO-
} tr,W)5O@L
} El<*)
=9a2+v0
A%.mIc.
//打印回应的头信息 l}z<q
public void logResponseHead(HttpURLConnection con) Dd5 9xNKm
{ 4$&l`yWU+
for(int i=1;;i++) /=/Ki%hh
{ )FQ"l{P
String header=con.getHeaderFieldKey(i); @=VxWU
if(header!=null) M-"j8:en
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _K~h? \u
Utility.log(header+" : "+con.getHeaderField(header)); LN5LT'CE
else DYr#?} 40
break; 4@?0wV
} Ocx"s\q(
} j1K3|E
w'H'o!*/
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public void splitterStop() 0 jth}\9
{ /]TNEU,K
bStop = true; &ry*~"xoh
} neI7VbH4
`uMEK>b
k <oB9J
} |NfFe*q0;8
^Qs}2%
MuY:(zC%
/* =#G 2}8mQD
**FileAccess.java N*-tBz
*//文件访问(定位，写) {q0+PzgP
package NetFox; u<BU4c/p
import java.io.*; -&8( MT*
&R72$H9C8i
lnZ{Ryo(
public class FileAccessI implements Serializable{ 5.~Je6K U
'8X>,un
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 S 5S\zTPIf
RandomAccessFile oSavedFile; 6ZQ |L=Ytp
long nPos; QQ3<)i
>j5\J_(;D
m+Ye`]
public FileAccessI() throws IOException +FTc/r
{ q9/v\~m
this("",0); q3$8"Q^
} [A-_?#cZ
Nn. 9J
dDaV2:4E
public FileAccessI(String sName,long nPos) throws IOException ~`OX}h/Z
{ D|LO!,=b
oSavedFile = new RandomAccessFile(sName,"rw"); y7,fFUKl
this.nPos = nPos; p&<Ssc
oSavedFile.seek(nPos); U6]#RxH
} ;t&q|}x"
l76=6Vtb
Xsq@E#@S
public synchronized int write(byte[] b,int nStart,int nLen) *'/,
{ P>7Xbm,VP
int n = -1; k)p`x"To
try{ B@,r8)D
oSavedFile.write(b,nStart,nLen); .q@?sdGD
n = nLen; &BVHQ7[
} Lzh8-d=HQ
catch(IOException e) xE1?)
{ bwsKdh
e.printStackTrace (); mk>; 3m*
} RaJTya^
+MoUh'/u
hhTtxC<:
return n; nh} Xu~#_
} TjW!-s?S
`fBQ?[05.
5PeS/%uT@
} ;,4*uU'vq
}%< ?]
Dp'urf\*$
/* uC'-: t#
**SiteInfoBean.java Ln&pe(c
*/ ;sB=f
package NetFox; Th)
-+".ut:R
I\@r~]+y
public class SiteInfoBean { *QC6zJ
7~h3B<
h[ .
private String sSiteURL; //Site's URL \((iR>^|
private String sFilePath; //Saved File's Path dfDjOZSL
private String sFileName; //Saved File's Name I5Vn#_q+b
private int nSplitter; //Count of Splited Downloading File `0d0T~
jl,gqMn"V
t;8)M$ p
public SiteInfoBean() DzZF*ylQ5P
{//nSplitter的缺省值为5 uF7vba$
//default value of nSplitter is 5 t7Q$
this("","","",5); Y)rK'OY'
} R3>q]
}LUvh
F&Md+2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 'n &p5%
{ `~GXK
sSiteURL= sURL; B>2=IZ
sFilePath = sPath; ^{Y,`F
sFileName = sName; eD>b|U=/
this.nSplitter = nSpiltter; +b|F_
k6tCfq;
$S6(V}yh
} Rh'z;Gyr
>q}3#TvP@
0Wr<l%M)+
public String getSSiteURL() 14,)JZN
{ s9?mX@>h
return sSiteURL; {53FR
} H=/1d.p
]iV]7g8:
<5zR-UA>
public void setSSiteURL(String value) oC&}lp)q
{ e{)giJY9
sSiteURL = value; odP<S.
} V.~kG ,Ht
&CG94
,ri&zbB
public String getSFilePath() RD`|Z~:q:K
{ )vtbA=RH?
return sFilePath; i~!g9o(
} W~ yb>+u
Gs:g
1 iH@vd
public void setSFilePath(String value) ']}-;m\
{ 5wK==hZ
sFilePath = value; 7K"3[.
} zteu{0
Kw fd S(
<J8c dB!e
public String getSFileName() ?eJ'$
{ *bK=<{d1P
return sFileName; Y>$5j}K
} e~vO
<&eJIz=
q;K]NP-_p
public void setSFileName(String value) @&*TGU
{ %Wtf24'o;v
sFileName = value; =ejcP&-V/
} |~9jO/&r
eaRa+ <#u
HNZ$CaJh
public int getNSplitter() XpAJP++
{ z_c-1iXCW
return nSplitter; $WYt`U;*lj
} ekx(i QA
[if(B\&
`xM*cJTZ
public void setNSplitter(int nCount) MTYV~S4/
{ ^#5'` #t
nSplitter = nCount; 9SC1A-nF
} d V%o:@Z
} (?Ku-k
/JNG}*
AD
/* J.iz%8
**Utility.java N XB8u6
*/ Uw4iWcC
package NetFox; BA a:!p
,ei9 ?9J1
6*,55,y
public class Utility { UP#@gxF
*zRig|k!H
shw?_#?1dy
public Utility() ^!tX+`,6^
{ T"\d,ug5[
N[@~q~v
*)[fGxz \
} bUgg2iFS
w5Fk#zJv
//线程睡眠 5c5!\g~'
public static void sleep(int nSecond) ;(K/O?nrJ
{ \J:+Wl.9A
try{ smCACQ$(
Thread.sleep(nSecond); gj;gl ="3
} f@sC~A. 9\
catch(Exception e) mxqZj8VuH
{ Gza= 0
e.printStackTrace (); R&1>\t
} _;}$/
} } W]A`-Jv
zFOtOz`9H
//日志 >s%Db<(P=
public static void log(String sMsg) fBX@ MedC
{ }w)}=WmD
System.err.println(sMsg); gLMb,buqC
} WX Fm'5Vr
W~H`{x%Av>
/[c_,G""
public static void log(int sMsg) /J}G{Y |n
{ $2FU<w$5
System.err.println(sMsg); U*nB= =
} wQW`Er3w
} "1|geO|
j&ti "|2\
)pI( <
/* G=qlE?j`j
**TestMethod.java FqyxvL.
*/ ,{IDf
package NetFox; (bm> )U=
Dp['U
Pjq'c+4.yL
public class TestMethod { C32*RNG?U
N-N]BS6
<=CABWO.
public TestMethod() rFcz0
{ ///xx/weblogic60b2_win.exe ~xzr8 P
try{ |i B#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #2|biTJ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); P}'B~~9W
SiteFileFetch fileFetch = new SiteFileFetch(bean); uznqq}
fileFetch.start(); }#g]qK
} /y1+aTiJ
catch(Exception e){e.printStackTrace ();} L%[>z'Zp
@nqM#
[<r.M<3
} b4:{PD~Mh
K1YxF
jNbVp{%/S}
public static void main(String[] args) h5P ]`r
{ vo Et\H
new TestMethod(); b1^wK"#
} nK< v
} (e_<~+E
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