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)); sF<4uy
} zF{z_c#3@
for(int i=0;i<nEndPos.length-1;i++) yXEC@#?|
{ Z>X-ueV
nEndPos = nStartPos[i+1]; ?VzST }
} L~0B
nEndPos[nEndPos.length-1] = nFileLength; FvvF4 ,e5
} `Zk?.1*2/
} Ng-3|N
Pd@?(WQ
^$T>3@rDB
//启动子线程 1= <Qnmw
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~Aq UT]l
for(int i=0;i<nStartPos.length;i++) :_?>3c}L
{ GJ((eAS)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bF}~9WEa
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `U;4O)`n
nStartPos,nEndPos,i); Nz]\%c/-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xUeLX`73
fileSplitterFetch.start(); F-ijGGL#
} A!j&g(Z"Q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~5JXY5*o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); i4uUvZf
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", IB?5y~+h
nEndPos = " + nFileLength); 9pk<=F
// fileSplitterFetch[nPos.length-1].start(); Z&21gN
Uh9$e
2} T"|56
//等待子线程结束 r?Z8_5Y
//int count = 0; &]ImO RN
//是否结束while循环 IRcZyry
boolean breakWhile = false; :Tjo+vw7$H
&1VC0"YJWy
>Vg<J~[g
while(!bStop) ^WVr@6
{ |#MA?oz3T
write_nPos(); JM!o(zbt
Utility.sleep(500); ,I)/ V>u
breakWhile = true; ?p}m[9@
mT)iN`$Y@
OP>'<FK
for(int i=0;i<nStartPos.length;i++) fwOvlD&e
{ ]^.#d
if(!fileSplitterFetch.bDownOver) jLZ~9FXF2
{ \a}%/_M\
breakWhile = false; N]5-#
break; !rwv~9I
} //AS44^IS
} #5'9T:8
if(breakWhile) @y}1%{,%
break; k.rZj|7 L
ymzlRs1^Ct
N.3M~0M*
//count++; }9@,EEhg
//if(count>4) }t]CDa_n
// siteStop(); s K s D
} /<M08ze
>0u4>=#
\5O4}sm$*
System.err.println("文件下载结束！"); :}j{NM#
} J;G+6C$:
catch(Exception e){e.printStackTrace ();} zf6k%
} :,:r
` NcWy
#:236^xYS
//获得文件长度 U?H!:?,C
public long getFileSize() _ea!psA0
{ +Pn+&o;D
int nFileLength = -1; )Ibp%'H
try{ EAx@a%
URL url = new URL(siteInfoBean.getSSiteURL()); rbs:qLa%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,qt9S0QS
httpConnection.setRequestProperty("User-Agent","NetFox"); ,AWN *OS
Joe k4t&0<
\J:/l|h
int responseCode=httpConnection.getResponseCode(); M"5,8Q`PkI
if(responseCode>=400) +MXI;k_
{ _kgw+NA&-H
processErrorCode(responseCode); wD"Y1?Mr
return -2; //-2 represent access is error \~U8<z
} JZN'U<R
41,Mt
W}nD#9tL
String sHeader; $I+QyKO9k
<{7B ^'
t&0pE(MO/
for(int i=1;;i++) FhS:.
{ ?MyXii<a
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); e=TB/W_
//Utility.log(in.readLine()); b6Dve]
sHeader=httpConnection.getHeaderFieldKey(i); kW5g]Q
if(sHeader!=null) =A04E
{ Ll%[}C?~]?
if(sHeader.equals("Content-Length")) $^}?98m
{ }"%tlU!}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Bo_Ivhe[m
break; 9>\s81^
} b=`h""u
} xR\$2(
else 05.^MU?^U
break; TU7Qt<
} LEWeybT
} 8`kK)iCq
catch(IOException e){e.printStackTrace ();} CR&v z3\Q
catch(Exception e){e.printStackTrace ();} -dZ7;n5&_
0vt?yD
R/xeC [r
Utility.log(nFileLength); MAQkk%6[g
U,~\}$<I
!z$.Jcr1
return nFileLength; Y6&w0~?!
} oaM $<
-6(C^X%
W{Ine> a'
//保存下载信息（文件指针位置） :WJ[a#
private void write_nPos() STL&ZO
{ O2-9Oo@#,
try{ G!uoKiL
output = new DataOutputStream(new FileOutputStream(tmpFile)); 6ix8P;;}#
output.writeInt(nStartPos.length); fOtL6/?
for(int i=0;i<nStartPos.length;i++) 8:|F'{<<b
{ AK} wSXF
// output.writeLong(nPos); I!|_C~I`2
output.writeLong(fileSplitterFetch.nStartPos); ?ep93:j
output.writeLong(fileSplitterFetch.nEndPos); >PGW>W$
} 5O%Q*\(
output.close(); NDWpV
} v&;q4b4
catch(IOException e){e.printStackTrace ();} ,dLh`t<\
catch(Exception e){e.printStackTrace ();} %!mJnc%
} NVAt-u0LB
yL7D;<!S&
u`O xY
//读取保存的下载信息（文件指针位置） P=OHiG\z
private void read_nPos() #;# V1
{ 4 >at#Zc
try{ yF0\$%H>$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); T6*naH
int nCount = input.readInt(); (i^{\zv
nStartPos = new long[nCount]; 4siNY4i"
nEndPos = new long[nCount]; gu7mGHn-
for(int i=0;i<nStartPos.length;i++) uckag/tv
{ yF8 av=<{
nStartPos = input.readLong(); P4-`<i]!S
nEndPos = input.readLong(); q;3.pRw(
} }_vE lBh6$
input.close(); BxS\"W
} vd6Y'Zk|F6
catch(IOException e){e.printStackTrace ();} 0GK<l
catch(Exception e){e.printStackTrace ();} yZj:Kp+7
} =* oFs|v
KuL2X@)}
4Z12Z@A#7
private void processErrorCode(int nErrorCode) M_<O'Ii3
{ <C`qJP-
System.err.println("Error Code : " + nErrorCode); CkKr@.dV
} 4C\>JGZvq
r({!ejT{U
PGF=q|j9K
//停止文件下载 *7u~`
public void siteStop() _~ZNX+4
{ /7/d u[P6
bStop = true; w7@fiH{
for(int i=0;i<nStartPos.length;i++) 3(0k!o0"
fileSplitterFetch.splitterStop(); ze@NqCF
(A|Gb2X
DK;p6_tT
} D~E1hr&Vd>
} a|Io)Qhr
//负责部分文件的抓取 tpOMKh.`
**FileSplitterFetch.java h,o/(GNnW
*/ $O9Nprf
package NetFox; u.ubw(vv
AIgJ,=9K
#Drs=7w
import java.io.*; Ab ,n^
import java.net.*; :vZ8n6J[
'Alt+O_
SR7$m<0t*
public class FileSplitterFetch extends Thread { 0*^ J;QGE
Cgq/#2BM
C8 9c2
String sURL; //File URL PY- 1 oP
long nStartPos; //File Snippet Start Position = _X#JP79
long nEndPos; //File Snippet End Position :34]}`-
int nThreadID; //Thread's ID `?r]OVe{y
boolean bDownOver = false; //Downing is over FKRO0%M4}Z
boolean bStop = false; //Stop identical #}*w &y
FileAccessI fileAccessI = null; //File Access interface ,#:*dl
6;6a.iZ
(hWr!(>C4]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \n$s5i-
{ 5G"LuA
this.sURL = sURL; o=@0Bd8
this.nStartPos = nStart; d$Y3 a^O|
this.nEndPos = nEnd; t\Pn67t
nThreadID = id; nm5zX,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 x(pq!+~K
} |U)m'W-(q
G347&F)
d*Q:[RUf,
public void run() HxCq6Y_m<
{ G8b/eWtP
while(nStartPos < nEndPos && !bStop) 5mxHOtvtWM
{ /J!C2
z(V?pHv+
D#Fe\8!l
try{ =%P'?(o|
URL url = new URL(sURL); acr@erk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); AT Dm$ *
httpConnection.setRequestProperty("User-Agent","NetFox"); U ?'$E\
String sProperty = "bytes="+nStartPos+"-"; E`s9SE
httpConnection.setRequestProperty("RANGE",sProperty); Rj6:.KEJ
Utility.log(sProperty); GPlAQk
:?W {vV
*qdf?'R
InputStream input = httpConnection.getInputStream(); hd{Vz{;W
//logResponseHead(httpConnection); jm9J-%?
]AkHNgW
7xz~%xC.
byte[] b = new byte[1024]; 9QE|p
int nRead; lCT N dW+=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 2c:H0O 0o
{ rw_T&>!
nStartPos += fileAccessI.write(b,0,nRead); dayp1%d
//if(nThreadID == 1) JA0$Fz
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m| 8%%E}d
} Q-;ltJ
N5 ITb0Tv
DwM4/m
Utility.log("Thread " + nThreadID + " is over!"); (}E-+:vFU
bDownOver = true; Cx$C+
//nPos = fileAccessI.write (b,0,nRead); {g9?Eio^F^
} {.F``2
catch(Exception e){e.printStackTrace ();} D~_|`D5WK
} `s74g0h
} kB_uU !G
]=ar&1}J
.C=&`;Vs
//打印回应的头信息 c*MSd
public void logResponseHead(HttpURLConnection con) "a;z
{ St/<\Y,wr
for(int i=1;;i++) "j|}-a
{ C {.{>M
String header=con.getHeaderFieldKey(i); _|%pe]St
if(header!=null) X&qRanOP;z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); JmN,:bI
Utility.log(header+" : "+con.getHeaderField(header)); sX53(|?*
else hCRW0 I
break; pl62mp!
} T{=.mW^ x
} tMGkm8y-A
s'%KKC
,Nl]rmI
public void splitterStop() Q]X0O10
{ 48,Aq*JFw
bStop = true; "h.}o DS
} ^$3 ~;/|
-f?Rr:#
B@!a@0,,_
} ]:TX> X!
),`MAevp
R<W#.mpo6
/* L'=e /&
**FileAccess.java \ZrLh,6f.
*//文件访问(定位，写) ~N+lI\K
package NetFox; m(JFlO
import java.io.*; xo{f"8}^
/_~b~3{u
a(CZGIB
public class FileAccessI implements Serializable{ #sit8k`GR8
:&$4&\_F
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 zSta!]
RandomAccessFile oSavedFile; pNpj, H*4
long nPos; #u+BjuZo
6w{^S~rqo
_DfI78`(
public FileAccessI() throws IOException 5vIuH+0
{ n0:+D R
this("",0); iqf+rBL
} $hB;r
)f#@`lf[<
Y{y #us1
public FileAccessI(String sName,long nPos) throws IOException ^EU&6M2
{ =!NYvwg6;o
oSavedFile = new RandomAccessFile(sName,"rw"); I%xrDiK97
this.nPos = nPos; A?Jm59{w
oSavedFile.seek(nPos); b7fP)nb695
} 'N,3]Soi
2L.UEAt
|E@Gsw
public synchronized int write(byte[] b,int nStart,int nLen) JA7HO|
{ &|<~J(L;
int n = -1; .UbmU^y|
try{ b><jhbv
oSavedFile.write(b,nStart,nLen); M"F?'zTkJ
n = nLen; ?!(/;RU1
} W.p->,N
catch(IOException e) @%J?[PG
{ G\h8j*o
e.printStackTrace (); )>at]mH
} lD2>`s5
@Zd+XWFw
%_+9y??
return n; `xe[\Z2
} :7Mo0,Bw,
4@#1G*OO
k1>%wR
} a AYO(;3
(omdmT%D
qcke8Q
/* q p|T,D%
**SiteInfoBean.java ><OdHRh@#
*/ z2t;!]"'l
package NetFox; lj%8(Xu
`(aU_r=
W"Dj+/uS
public class SiteInfoBean { $V?zJ:a>L
T,(IdVlJ
M "p6xp/
private String sSiteURL; //Site's URL 3hR7 ./
private String sFilePath; //Saved File's Path '.~vN L+ O
private String sFileName; //Saved File's Name Ed#%F-1sX
private int nSplitter; //Count of Splited Downloading File (d993~|h
tZ>>aiI3
DLyHC=%{+h
public SiteInfoBean() 6 6x} |7
{//nSplitter的缺省值为5 LYh5f#
//default value of nSplitter is 5 4M(w<f\5F
this("","","",5); F~a5yW:R=)
} ^w2n
Pb} &c
t,N-|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .5L/<
{ s5|LD'o!
sSiteURL= sURL; w;H
sFilePath = sPath; wO} 3i6
sFileName = sName; R2Tvo?xI7
this.nSplitter = nSpiltter; ?-<t-3%hyV
"r cPJX
<)Kjf/x
} \, n'D
BO[Q"g$Kon
X_s;j5ur
public String getSSiteURL() H#U{i
{ i40r}?-
return sSiteURL; avO+1<`4B
} ABhza|
DJ}xD&G
^.kas7<
public void setSSiteURL(String value) qa^x4xZM
{ 0x^$q? \A
sSiteURL = value; T<zonx1
} spO?5#
o~P8=1t
3}g?d/^E3
public String getSFilePath() k`)LO`))
{ M#S8x@U
return sFilePath; 3Un/-4uL
} F]yclXf('
c'`7p/l.
/UyW&]nK
public void setSFilePath(String value) w0/W=!_
{ 58e{WC
sFilePath = value; Zy*}C,Z
} f+xGf6V
m_rRe\
.e.vh:Sz
public String getSFileName() qx0o,oZN!
{ V<4)'UI?k9
return sFileName; (!X:[Ah*$
} u6r-{[W}
xDADJ>u2K
m$LZ3=v%8
public void setSFileName(String value) W\~ZmA.
{ 73}k[e7e
sFileName = value; <S$y=>.9
} w5n>hz_5
8QC:ro
iT^lk'?{O
public int getNSplitter() P#ru-0DD
{ y_$^Po
return nSplitter; L6 _Sc-sU
} ;k/0N~
pNiqb+^nz
7KM!\"PM
public void setNSplitter(int nCount) ?!~au0
{ jHz]
nSplitter = nCount; gP1$#KgU
} UO:>^,(j
} BM&'3K_y
gX(QRQ
v?LJ_>hw*T
/* }_?7k0EZ@
**Utility.java eazP'(rc
*/ ;4qalxzu
package NetFox; ZN4&:9M
_cGiuxf #
}f-rWe{gs>
public class Utility { IL%&*B
r1?LKoJOn
%;W8;
public Utility() m9e$ZZG$
{ !h4So4p
^Ws~h\{%
0]HK(,/h
} :sA-$*&x
sg6cq_\
//线程睡眠 -5>g 0o2
public static void sleep(int nSecond) &H+<uYV
{ 5~[Fh2+
try{ 7L<oWAq
Thread.sleep(nSecond); @~N#)L^
} P2s0H+<
catch(Exception e) @K+u+} R
{ *v5y]E%aW
e.printStackTrace (); a9qZI
} g)p[A 4
} =G72`]#-
cxv)LOl-
//日志 Hd2_Cg FB
public static void log(String sMsg) s~63JDy"E
{ S7SPc
System.err.println(sMsg); (6A{6_p
} rpXw 8
QB@*/Le
ome>Jbdhe
public static void log(int sMsg) jS- QTG!=
{ eBN>|mE4N
System.err.println(sMsg); 1bDc ct
} ]D]K_`!K
} eb8_guZ
b~~}(^Bg
2'}2r ~6
/* ypifXO;m7
**TestMethod.java < 1r.p<s
*/ LaIif_fie^
package NetFox; ){(cRB$
SMy&K[hJ[
LpiLk| 2i
public class TestMethod { d)AkA\neWo
a*D|$<V
QMsnfG
public TestMethod() EPg?jKZava
{ ///xx/weblogic60b2_win.exe +I~?8*
try{ D"WkD j"M
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); x-QP+M`Pu
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); qqAsh]Z
SiteFileFetch fileFetch = new SiteFileFetch(bean); tO0+~Wm
fileFetch.start(); }hf*Jw
} =0-qBodbl
catch(Exception e){e.printStackTrace ();} }v!6BU6<Q
0qZ)$YKq
g[n8N{s
} FPMk&
;K_B,@:'
ditzl(L
public static void main(String[] args) V:+bq`
{ 0CR;t`M@
new TestMethod(); ;|%r!!#-t
} d"cfSH;h
} (M=Br
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