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)); mWYrUI
} ]QHp?Ii1
for(int i=0;i<nEndPos.length-1;i++) 5,p;b
{ EPn!6W5^
nEndPos = nStartPos[i+1]; 5-GS@fY
} "`cN k26JZ
nEndPos[nEndPos.length-1] = nFileLength; f8[O]MrO;
} ;G}
} 'fl.&"/r
{H(l"KuL
.xwskzJ3
//启动子线程 E,tdn#_|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; OnE%D|Tq=
for(int i=0;i<nStartPos.length;i++) "~r)_Ko
{ , d $"`W2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $.C-_L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), >U`G3(#7S
nStartPos,nEndPos,i); >v, si].
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pl3ap(/
fileSplitterFetch.start(); Lu6g`O:['
} ?e6>dNw
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [m{sl(Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %m dtVQ@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", J;Z2<x/H
nEndPos = " + nFileLength); O<Q8%Az
// fileSplitterFetch[nPos.length-1].start(); &kzysv-_
M1WD^?tKQ.
z]rr Q=dAA
//等待子线程结束 m-azd~r[
//int count = 0; +@^);b6
//是否结束while循环 l3p :}A
boolean breakWhile = false; 3s?u05_
NW5OLa")J<
Q;VuoHj!
while(!bStop) o/7u7BQl2
{ Le?g,c
write_nPos(); >Y8\f:KQ
Utility.sleep(500); uarfH]T{
breakWhile = true; xE@/8h
So!=uYX
2`riI*fQ
for(int i=0;i<nStartPos.length;i++) QPB,B>Z
{ ;$&\:-6A#
if(!fileSplitterFetch.bDownOver) 2kDY+AN;
{ F4G81^H
breakWhile = false; v]{UH{6
break; =MQ/z#:-P
} YhV<.2^k
} "g5{NjimY
if(breakWhile) F<b'{qf"
break; ':;k<(<-
tgG*k$8z
?110} [jw
//count++; YyxU/UnhG
//if(count>4) K [DpH&
// siteStop(); 2%fIe
} 0c`zg7|
$4xSI"+M%
y& yf&p
System.err.println("文件下载结束！"); jG7PT66>;
} Sj~SG
catch(Exception e){e.printStackTrace ();} ="YGR:
} G*+^b'7
mTI`^e
o5a=>|?p>
//获得文件长度 7xeqs q
public long getFileSize() YS^!'IyG/B
{ O_1[KiZ
int nFileLength = -1; _Z[0:4
try{ z5$Q"Y.D
URL url = new URL(siteInfoBean.getSSiteURL()); PhC3F4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :CE4< {V
httpConnection.setRequestProperty("User-Agent","NetFox"); KL=<s#
U&WEe`XM
0pMN@Cz6
int responseCode=httpConnection.getResponseCode(); '+_>PBOc
if(responseCode>=400) cw!,.o%cD
{ =D$ED^W
processErrorCode(responseCode); =^u;uS[IW
return -2; //-2 represent access is error *"w hup[
} 4l ZK@3
0i_:J
klJ21j0Bb2
String sHeader; rT[qh+KWe
2.z-&lFBZ
qMJJBl
for(int i=1;;i++) >E+g.5 ,:W
{ W#<1504ip
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); RJ3oI+gI
//Utility.log(in.readLine()); pc*)^S
sHeader=httpConnection.getHeaderFieldKey(i); /jGBQ-X
if(sHeader!=null) hNN[djR
{ /dYv@OU?
if(sHeader.equals("Content-Length")) p@G7}'|eyA
{ V,_m>$Mo
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )6)bI.BY
break; W\kli';jyC
} y,nmPX?]n
} VQla.Y
else V_SH90@)+
break; z/{X{+Z
} h) Wp
} =Hd yra
catch(IOException e){e.printStackTrace ();} n6%`
catch(Exception e){e.printStackTrace ();} DRQx5fgL
J|q(HpB
mtv8Bm=<
Utility.log(nFileLength); @[3c1B6K
S\TXx79PhC
YGyv)\
return nFileLength; ps 3)d
} 3 39q%j$
?A3L8^tR
%rptI$^*X
//保存下载信息（文件指针位置） }9S}?R
private void write_nPos() 0y9 b0G
{ p' >i3T(
try{ lDYgtUKG
output = new DataOutputStream(new FileOutputStream(tmpFile)); [7v|bd
output.writeInt(nStartPos.length); 5^Qa8yA>7
for(int i=0;i<nStartPos.length;i++) lv 8EfN
{ _HUbE /
// output.writeLong(nPos); C[^V\?3ly:
output.writeLong(fileSplitterFetch.nStartPos); :k/Xt$`
output.writeLong(fileSplitterFetch.nEndPos); 2 kDsIEA
} G|g^yaq>
output.close(); nQc#AFg
} @yuiNj.T
catch(IOException e){e.printStackTrace ();} bT.q@oU
catch(Exception e){e.printStackTrace ();} "Q.*
} R_PF*q2 '
s/D)X=P1
.hat!Tt9
//读取保存的下载信息（文件指针位置） "@UQSf,
private void read_nPos() vamZKm~p
{ q\6(_U#Tl
try{ D`LBv,n
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Q7865
int nCount = input.readInt(); xR1G
nStartPos = new long[nCount]; 4KH492Nq9
nEndPos = new long[nCount]; W" 5nS =d%
for(int i=0;i<nStartPos.length;i++) )Z/"P\qo
{ OldOc5D
nStartPos = input.readLong(); WkTJ M
nEndPos = input.readLong(); NHGTV$T`1
} \]9)%3I
input.close(); 7N9NeSH
} )dT@0Ys%
catch(IOException e){e.printStackTrace ();} Vx_33";S\
catch(Exception e){e.printStackTrace ();} [%P#ieD4
} CZ5\Et6r
%T/@/,7h
KrE'M
private void processErrorCode(int nErrorCode) ntW@Fm:bw>
{ n"(!v7YNp
System.err.println("Error Code : " + nErrorCode); P=94
} s\-,RQ1
(GSP3KKo*G
Cu[-<>my
//停止文件下载 (>v'0RA
public void siteStop() )j_El ]?
{ M5^Y W#e
bStop = true; 1-_r\sb
for(int i=0;i<nStartPos.length;i++) &3Zq1o
fileSplitterFetch.splitterStop(); js_`L#t
3'4+3Xo
V%s g+D2
} 8+F5n!
} WTvUz.Et
//负责部分文件的抓取 ot^pxun
**FileSplitterFetch.java @5%&wC
*/ `S {&gl
package NetFox; `geHSx_
]\78(_o.zz
kWzN {]v
import java.io.*; EbC!tR
import java.net.*; JVE\{ e)
qLN\%}69/
||$&o!;/L
public class FileSplitterFetch extends Thread { cr1x CPJj
?%,NOX
*G19fJ[5
String sURL; //File URL m@4Dz|
long nStartPos; //File Snippet Start Position 6\4-I^=B
long nEndPos; //File Snippet End Position \|;\
int nThreadID; //Thread's ID /at7H!
boolean bDownOver = false; //Downing is over CXlbtpK2k
boolean bStop = false; //Stop identical qkb'@f=
FileAccessI fileAccessI = null; //File Access interface NX @FUct;
Z>rY9VvWD
nr!N%Hi
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException g52a vG
{ ^#/FkEt7bp
this.sURL = sURL; %MHb
this.nStartPos = nStart; U&5*>fd=
this.nEndPos = nEnd; #.Rn6|V/4
nThreadID = id; XjX
fileAccessI = new FileAccessI(sName,nStartPos);//定位 l:85 _E
} /(N/DMl[
isQ(O
t[^$F,
public void run() ~3&{`9Y
{ %ByPwu:f
while(nStartPos < nEndPos && !bStop) ~4~`bT9
{ n>M`wF>
.w2ID
.Mt3ec<
try{ tq3Wga!5
URL url = new URL(sURL); }r,\0Wm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4.RQ3SoDa
httpConnection.setRequestProperty("User-Agent","NetFox"); zKJ2~=
String sProperty = "bytes="+nStartPos+"-"; .|UQ)J?s
httpConnection.setRequestProperty("RANGE",sProperty); {Cx5m
Utility.log(sProperty); xUo6~9s7
k:@DK9 "^
$<}c[Nm
InputStream input = httpConnection.getInputStream(); #~u0R>=
//logResponseHead(httpConnection); 8K 3dwoT
M([#Py9h
(Fv tL*
byte[] b = new byte[1024]; xs$$fPAQ
int nRead; n<I{x^!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) iGN\ >m}
{ _fGTTw(
nStartPos += fileAccessI.write(b,0,nRead); cnv>&6a)
//if(nThreadID == 1) tXD$HeBB?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bzgC+yT
} \o9 \ikR
zw0w."V
_VtQMg|u
Utility.log("Thread " + nThreadID + " is over!"); {zdMmpQF
bDownOver = true; c'2d+*[
//nPos = fileAccessI.write (b,0,nRead); rqdwQ
} !rvEo =^
catch(Exception e){e.printStackTrace ();} ~wc:/UM|
} v9*m0|T0M
} JxAQ,oOO
qWt}8_"
-yYdj1y;
//打印回应的头信息 N;7/C
public void logResponseHead(HttpURLConnection con) `8:0x?X
{ nwRltK
for(int i=1;;i++) 7e/+C{3v
{ [K!9xM6
String header=con.getHeaderFieldKey(i); Gr"CHz/
if(header!=null) ?1e{\XW
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8[^'PIz
Utility.log(header+" : "+con.getHeaderField(header)); QTV*m>D
else .n-#A
break; y8Va>ul"U
} FL0uY0K
} yV30x9i!2
I.2J-pu}
|{jT+
public void splitterStop() Jd2.j?P=
{ ']]d-~:
bStop = true; r~w.J+W
} 39pG-otJ
*7BfK(9T
k;WD[SV
} /?\3%<vn
G dgL}"*F
FMfpjuHk
/* Hvl n>x@
**FileAccess.java Wboh2:TH:
*//文件访问(定位，写) k4TWfl^}9
package NetFox; W:w~ M'o
import java.io.*; s}D>.9
=W(*0"RM
8a)AuAi?!
public class FileAccessI implements Serializable{ OMGggg
G=dzP}B'WA
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 a QH6akH
RandomAccessFile oSavedFile; gr=h!'m
long nPos; %x)bZ=An
+2tQFV;
+^)v"@,VP
public FileAccessI() throws IOException oFY!NMq}:
{ ON?Y Df
this("",0); D$>_W,*V
} ,pNx(a
c/{FDN
>.h:Y5
public FileAccessI(String sName,long nPos) throws IOException ,Z.sGv
{ Rx%S<i;9
oSavedFile = new RandomAccessFile(sName,"rw"); ^5mc$~1`
this.nPos = nPos; L9x-90'q,
oSavedFile.seek(nPos); v gN!9
} !>UlvT-
{Gxe%gu6K
7 ,Rg~L
public synchronized int write(byte[] b,int nStart,int nLen) :Pud%}'
{ )?n'ZhsX
int n = -1; "Fz.#U
try{ "gM^o
oSavedFile.write(b,nStart,nLen); >rnVTK
n = nLen; U"oNJ8&%|
} |WS)KR !
catch(IOException e) n*4`Tduu^
{ "LyD
e.printStackTrace (); cby#
} i`,FXF)
;C]Ufk
h}b:-a
return n; xNz(LZ.c
} #-hO\ QdC
*kr/,_K
x2"iZzQlD
} LQ0/oYmNc
yNu_>!Cp5
{.Tx70kn
/* ^l &lwSRVt
**SiteInfoBean.java 6( HF)z
*/ [P$Xr6#
package NetFox; UA[`{rf
DA=!AK>
tDByOml8Ix
public class SiteInfoBean { -[>de! T3$
{C1crp>q
!iXRt")
private String sSiteURL; //Site's URL \1EuHQ?
private String sFilePath; //Saved File's Path b*|~F
private String sFileName; //Saved File's Name mh }M|h5Im
private int nSplitter; //Count of Splited Downloading File 9+.wj/75
D0. )%
%E?Srs}j
public SiteInfoBean() Vns3859$8
{//nSplitter的缺省值为5 ~^t@TMk$
//default value of nSplitter is 5 HDVimoOq
this("","","",5); 8`=?_zF
} {@Wv@H+4
%idBR7?`g
7Q 3!=b
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5=>1>HYM
{ 9>}&dQ8
sSiteURL= sURL; dBWny&
sFilePath = sPath; b F=MQ
sFileName = sName; s.3"2waZ=T
this.nSplitter = nSpiltter; 3G})$y3m
P8 X07IK
Ik G&
} A^U84kV=
OV>&`puL
^@fD{]I
public String getSSiteURL() ,0l Od<
{ U,<m%C"
return sSiteURL; l.YE@EL
} fHt\KP
'K[ml ?_
bQ<qdGa
public void setSSiteURL(String value) <'y<8gpM
{ }\4yU=JPK
sSiteURL = value; )'shpRB;1
} -YoL.`s1
w,{h9f
6jE.X
public String getSFilePath() &OR(]Wt0
{ ;$p!dI\-Q
return sFilePath; MBLZ:A| C
} xJq|,":gj
q8 v iC|
rxCzPF
public void setSFilePath(String value) N:j7J
{ RQ+,7Ir
sFilePath = value; !V|{(>+<
} (m]l -Re
8PI%Z6
G|i0n
public String getSFileName() ~id6^#&>
{ 4,RPidv%O
return sFileName; E^8|xT'h6
} ;QI9OcE@/
lu=a e<M
wMa8HeBE\
public void setSFileName(String value) %ms%0%
{ U-|]A\`)I
sFileName = value; ly0R'4j \
} TrI+F+;
y^2#;0W
qHt/,w='Q
public int getNSplitter() VKa+[
{ *d._H1zT
return nSplitter; '%$Vmf)=
} 2>z YJqG|
}YwaN'3p!
1?@HOu
public void setNSplitter(int nCount) /9vi
{ AXyXK??
nSplitter = nCount; B,b8\\^k|
} WjD885Xo
} J)nK9
mhbczVw
>ohCz@~
/* 41 F;X{Br
**Utility.java y oW~
*/ .?}M(mL
package NetFox; c*KE3:
~IhAO}1
9a`LrB
public class Utility { M/S~"iD
<q63?Ms'
\gA!)q.;
public Utility() ~^wSwd[
{ :saP :&
]b-2:M
)O'LE&kQ|
} {f06Ki
@SfQbM##%
//线程睡眠 IDct!53~
public static void sleep(int nSecond) k 9i W1
{ :EX>Y<`]
try{ fWHvVyQ.
Thread.sleep(nSecond); 17hoX4T
} ZTmy}@l
catch(Exception e) NcA `E_3
{ ljFq;!I5
e.printStackTrace (); d/_D|ivZ=
} ki1(b]rf
} x0j5D
P&`%VW3E
//日志 N'{[BA(eE
public static void log(String sMsg) Ejug2q
{ =\Q<TY
System.err.println(sMsg); Eq-+g1a
} <':h/d
}`R,C~-|^
uq5?t
public static void log(int sMsg) 4`O[U#?
{ w>W#cTt
System.err.println(sMsg); 20Zxv!
} Zue3Z{31T
} OP/DWf
JFv70rBe
SxF'2ii
/* aH}/+Hu-
**TestMethod.java $6Ma{rC|
*/ RELNWr
package NetFox; *aErwGLB8
.W]k8N E
CR4O#f8\
public class TestMethod { Avx`
i'fw>-0
cSL6V2F
public TestMethod() IQ_6DF
{ ///xx/weblogic60b2_win.exe ; Y/nS
try{ j!+jLm!l
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %q5dV<X'c
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Q4XlYgIV2A
SiteFileFetch fileFetch = new SiteFileFetch(bean); oh5'Isb$
fileFetch.start(); sL@\,]Y
} SZGR9/*^
catch(Exception e){e.printStackTrace ();} ]_C"A
Pe`mZCd^
h@RpS8!Bi
} YsmRY=3
fcq8aW/z_
HK)m^!=
public static void main(String[] args) 461g7R%r
{ 8063LWV
new TestMethod(); SkuR~!
} b<FE
} ('x]@
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