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)); vTx2E6
} ikSt"}/hd
for(int i=0;i<nEndPos.length-1;i++) -xA2pYz"
{ PJL=$gBgKk
nEndPos = nStartPos[i+1]; Rw:*'1
} HEM9E&rL
nEndPos[nEndPos.length-1] = nFileLength; }=]M2}
} 3S}Pm2D2
} tyqT
?pB>0b~3-
4Q6mo/=H
//启动子线程 d*%`!G
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &?yZv{
for(int i=0;i<nStartPos.length;i++) VQS~\:1
{ I\$X/t +dH
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), cbT7CG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), K%RxwM
nStartPos,nEndPos,i); #a8B/-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VN\W]jT
fileSplitterFetch.start(); (j3xAA
} suzZdkMA
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 65aK2MS@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %YC_Se7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1BpiV-]=
nEndPos = " + nFileLength); hj.a&%
// fileSplitterFetch[nPos.length-1].start(); ?3.b{Cq{-
/VN f{p
]33>m|?@
//等待子线程结束 ^>hWy D
//int count = 0; lUvpszH=
//是否结束while循环 zp%Cr.)$
boolean breakWhile = false; TO?R({yx*
7OJ'){R$
Gf<'WQ[
while(!bStop) ikvWh<=>H
{ r 0iK
write_nPos(); l)&X$3?tz
Utility.sleep(500); esMX-.8Cx
breakWhile = true; ap+JQ@b
s pp f
~2QR{; XQ
for(int i=0;i<nStartPos.length;i++) }%_ b$
{ \}"$ ?d'f
if(!fileSplitterFetch.bDownOver) ~U@;gLoD
{ n4R(.N00
breakWhile = false; io-![^{
break; LH8 fBhw
} J2xw) +
} ~ijVmWNk
if(breakWhile) [Q/TlOt5
break; ov_j4j>6P
j;-1J_e5
?-dX`n
//count++; ;E3>ay6m8
//if(count>4) <?riU\-]y
// siteStop(); $4 S@
} [nrYpb4
dE4L=sTEsy
sE Q=dcK
System.err.println("文件下载结束！"); 3 +G$-ru
} U<_3^
catch(Exception e){e.printStackTrace ();} =pS5uR~
} 5',8 ziJQ
)W;o<:x3
G <i@ 5\#
//获得文件长度 @W[f1
public long getFileSize() ?7.7`1m!v
{ eQp4|rf
int nFileLength = -1; KmA;HiH%J
try{ yl7&5)b#9
URL url = new URL(siteInfoBean.getSSiteURL()); 0c<.iM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d\R,Q
httpConnection.setRequestProperty("User-Agent","NetFox"); %)/P^9I6
;kS&A(
e} P I^bc
int responseCode=httpConnection.getResponseCode(); "J[K 3
if(responseCode>=400) |ZRagn30
{ lFV N07hG
processErrorCode(responseCode); $ us]35Z3
return -2; //-2 represent access is error Af'" 6BS
} LXC9I/j/
7|$:=4
pEIRh1
String sHeader; GS a[ oh
;h*K}U
`Nb[G)Xh
for(int i=1;;i++) Kgi<UkFP
{ X[&Wkr8x '
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }NzpiY9
//Utility.log(in.readLine()); #t:S.A@
sHeader=httpConnection.getHeaderFieldKey(i); XBb~\p3y
if(sHeader!=null) KLitg6&P
{ 8&?s#5zA
if(sHeader.equals("Content-Length")) i]6`LqlO
{ ->g*</
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); '%dfzK*Z
break; x,|hU@h
} #><.oreXq
} V-Sd[
else h?BFvbAt
break; T"E6y"D
} i+S) K
} YW_Q\|p]M
catch(IOException e){e.printStackTrace ();} 1m:XR0P
catch(Exception e){e.printStackTrace ();} aTqd@},?
V )x$|!(
D6>2s\:>vp
Utility.log(nFileLength); GVYBa_gx
\]2]/=2tLd
\Zqng
return nFileLength; mpuq 9)6
} YaKeq5%y
TgmnG/Z
M<.d8?p )
//保存下载信息（文件指针位置） QS` PpyBkd
private void write_nPos() G~2jUyv
{ B8V>NvE~o
try{ 4E]l{"k<
output = new DataOutputStream(new FileOutputStream(tmpFile)); aWWU4xe
output.writeInt(nStartPos.length); mKL<<L[
for(int i=0;i<nStartPos.length;i++) Li/O
{ rV R1wsaL
// output.writeLong(nPos); Mc09ES
output.writeLong(fileSplitterFetch.nStartPos); 5Iy;oZ
output.writeLong(fileSplitterFetch.nEndPos); K]s[5
} C":32_q
output.close(); Gb#Cm]
} F+,~v-
catch(IOException e){e.printStackTrace ();} }z _
catch(Exception e){e.printStackTrace ();} "$ Y_UJT7
} jkiFLtB@V
{*0<T|<n
![YX]+jqNp
//读取保存的下载信息（文件指针位置） @eD):Y
private void read_nPos() tD(7^GuR
{ +cgSC5nR
try{ OjJXysslXO
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); h|VeG3H
int nCount = input.readInt(); <lw` 3aa(
nStartPos = new long[nCount]; j9?}j#@
nEndPos = new long[nCount]; EQb7-vhg
for(int i=0;i<nStartPos.length;i++) 3DiLk=\~
{ wQP^WzNE
nStartPos = input.readLong(); e vrXo"3
nEndPos = input.readLong(); [SHXJ4P*
} %k-3?%&8
input.close(); ein4^o<f.
} Kwefs;<E?
catch(IOException e){e.printStackTrace ();} \Xm,OE_v"
catch(Exception e){e.printStackTrace ();} &]e'KdXF
} s2'yY(u/
q>$ev)W
DnCP aM4%
private void processErrorCode(int nErrorCode) iYORu3
{ AsAT_yv#
System.err.println("Error Code : " + nErrorCode); )6,de2Pb
} yj;sSRT
l6YtEHNG
qq) rd
//停止文件下载 I/d&G#:~
public void siteStop() x }\64
{ k7?N ?7w
bStop = true; 'Jt]7;04p
for(int i=0;i<nStartPos.length;i++) ^?cz,N~
fileSplitterFetch.splitterStop(); !46RGU:I
k9 "[H'
WN{ 9
} cik!GA
} Pz>s6 [ob
//负责部分文件的抓取 !c}O5TI|#
**FileSplitterFetch.java hd>aZ"nm1
*/ _/uFsYC
package NetFox; PD&\LbuG
rai3<_W<
CdasP9"1
import java.io.*; y4*U6+#.
import java.net.*; A'q#I>j`
C8[&S&<_<
&Q;sSIc
public class FileSplitterFetch extends Thread { Ss~;m']68
:=/85\P0SU
i@P)a'W_
String sURL; //File URL p2n0Z\2
long nStartPos; //File Snippet Start Position @hJ%@(
long nEndPos; //File Snippet End Position ';TT4$(m
int nThreadID; //Thread's ID b8V~S'6VqO
boolean bDownOver = false; //Downing is over C ~<'rO}|
boolean bStop = false; //Stop identical c(:f\Wc3Z
FileAccessI fileAccessI = null; //File Access interface @ zs'Y8
^T ?RK"p
c_-drS
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException WFO4gB*
{ }4Tc
this.sURL = sURL; AvxfI"sp
this.nStartPos = nStart; 3HLNCt09
this.nEndPos = nEnd; Xf02"PXC
nThreadID = id; : >6F+XZ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 b7NM#Hb
} &y3OR1_Sm*
g .onTFwN
lJu;O/
public void run() )2V:
{ eoai(&o0$
while(nStartPos < nEndPos && !bStop) (eCJ;%%k
{ }`W){]{kO
?&|5=>u2}$
*+j*{>E
try{ dRj|g
URL url = new URL(sURL); LV\DBDM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xl6,s>ob
httpConnection.setRequestProperty("User-Agent","NetFox"); giZP.C"0
String sProperty = "bytes="+nStartPos+"-"; M,/mE~
httpConnection.setRequestProperty("RANGE",sProperty); 3&u&x(
Utility.log(sProperty); \@8+U;d
n#q<`}u,
*pAV2V(!23
InputStream input = httpConnection.getInputStream(); :bz}c48%
//logResponseHead(httpConnection); [z9`)VIe
eZ|%<Wpu
|$Xl/)Oq
byte[] b = new byte[1024]; >#hO).`C
int nRead; FN\E*@>X=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) CjlKMbnBH
{ h3bff#<K
nStartPos += fileAccessI.write(b,0,nRead); LXbP 2
//if(nThreadID == 1) t?}zdI(4
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^.1c{0Y^0
} 7on.4/;M
J4Nln
AtdlZ
Utility.log("Thread " + nThreadID + " is over!"); ]|MEx{BG-
bDownOver = true; .Xce9C0SW
//nPos = fileAccessI.write (b,0,nRead); k\WR ]
} 1#.>a$>
catch(Exception e){e.printStackTrace ();} G'6@+$ppS
} Qp/QaVQ+
} BRlT7grgq
2^^`n1?'
9?0^ap,T
//打印回应的头信息 ``ou/Z
public void logResponseHead(HttpURLConnection con) vg3=8>#
{ _9=Yvc=
for(int i=1;;i++) =bHD#o|R
{ [-\%4
String header=con.getHeaderFieldKey(i); XmEq2v
if(header!=null) kuol rfGB
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;?8_G%va
Utility.log(header+" : "+con.getHeaderField(header)); ^c&L,!_)H
else Wn(6,MDUN
break; kO|L bQ@=q
} oW<5|FaN
} 9\/xOwR
\~fONBY
{5F-5YL+>
public void splitterStop() ^ q<v{_
{ $e*ce94
bStop = true; m|{3),#V
} ~C>?W[Y
w+yC)Rmz
F)W:
} !{^PO<9
S4G^z}{_
@7?#Y|`
/* DpUbzr41+k
**FileAccess.java #7MUJY+ 9
*//文件访问(定位，写) KTP8?Q"n0
package NetFox; cUvz2TK
import java.io.*; `-3Ow[
m06ALD_
3wC' r
public class FileAccessI implements Serializable{ :.$3vaZ@
}[4r4 1[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~g5[$r-u-u
RandomAccessFile oSavedFile; 8=gjY\Dp
long nPos; M+w=O!dq
ptU\[Tq
*T5!{
public FileAccessI() throws IOException w]]8dz
{ UPG9)aF
this("",0); DP3PYJ%+B
} =~=*&I4Dp
y *fDwd~
f}x.jxY?
public FileAccessI(String sName,long nPos) throws IOException H^s<{E0<
{ n p\TlUc
oSavedFile = new RandomAccessFile(sName,"rw"); paKSr|O
this.nPos = nPos; k} |
oSavedFile.seek(nPos); )pq;*~IBI
} =5kY6%E7c
Mz~M3$$9n
OoA|8!CFa
public synchronized int write(byte[] b,int nStart,int nLen) nv@8tdrc
{ ~c %hWt
int n = -1; kic/*v\6@
try{ YgUvOyaQXf
oSavedFile.write(b,nStart,nLen); 5u*-L_
n = nLen; no< ^f]33
} @>W(1mRi
catch(IOException e) Z@]e{zO
{ . r[Hu40p
e.printStackTrace (); +f@U6Vv
} cd$m25CxC
a{ ?`t|
{TX]\ufG
return n; z7Q?D^miy
} NhaI<J
kPF9Z "l
(Q.waI
} T>R0T{A
1T-8K r
.y@oz7T5
/* wPwXM!
**SiteInfoBean.java *=+td)S/1
*/ *#tJM.Z
package NetFox; <8d^^0
<N_+=_
IE9XU9Kd
public class SiteInfoBean { W9D86]3Y
j(RWO
E )5E$
private String sSiteURL; //Site's URL =jX8.K4]
private String sFilePath; //Saved File's Path 1:f9J
private String sFileName; //Saved File's Name Z|5?7v;h5
private int nSplitter; //Count of Splited Downloading File }M3fmAP}
,PWgH$+
v"OY 1<8
public SiteInfoBean() u%$Zqee
{//nSplitter的缺省值为5 1oN^HG6O
//default value of nSplitter is 5 J|w\@inQ
this("","","",5); ^OstR`U3
} {j:hod@-:5
W!?7D0q
PzA|t;*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~~SwCXZ+b^
{ >i5acuth
sSiteURL= sURL; b0Kc^uj5
sFilePath = sPath; 0Sgaem`
sFileName = sName; :yeq(oK,
this.nSplitter = nSpiltter; {`K m_<Te!
QrYpZZ;
* v75O7l
} {a4z2"\A
)0Me?BRp
JWMpPzs
public String getSSiteURL() N(y\dL=v
{ q^r#F#*1l
return sSiteURL; 89wU-Aggq
} oE(7v7iY
Fl1;;F
= Wu *+paQ
public void setSSiteURL(String value) bZ|FnY}FB
{ UmQ?rS8d
sSiteURL = value; 6bBB/yd
} t=-SH^$SR
|=$-Wu
+eX@U;J,g
public String getSFilePath() 4)U.5FBk )
{ ?84 s4BpV1
return sFilePath; .R9IL-3fO
} [BT/~6ovrZ
Qt/8r*Oe
Z| V`B `
public void setSFilePath(String value) 3AsT
{ z&{5;A}Q@
sFilePath = value; rxy&spX
} U5He?
7LU}Iiv
\'CDRr"uw
public String getSFileName() 2EfF=Fm>
{ S6AU[ASY.
return sFileName; XwlbJ=mf
} aEWWFN
4(1(e
;~\MZYs3m
public void setSFileName(String value) SL;9Q[
{ ~d6DD;`K
sFileName = value; 3Ei5pX=g
} 'ul~7h;n
Ygl%eP%Z
}C#;fp"L
public int getNSplitter() opJMS6%r
{ bIEhgiH
return nSplitter; tWoh''@#
} GF5^\Rf
E5N{j4\F
ea~:}!-P
public void setNSplitter(int nCount) OBP1B@|l$+
{ bf!M#QOk?
nSplitter = nCount; FDv+*sZ
} sH?/E6
} FN%m0"/Z{t
V`7FKL@"
d\FJFMW*9
/* 5GPo*Qpl
**Utility.java >$,y5 AJ&
*/ N1}={yF.fQ
package NetFox; N~NQ6:R[
=?s3iP
i![dPM
public class Utility { [g Z"a*
ty*@7g0k
}-o{ASC#
public Utility() y:h}z).
{ C,pJ`:P
'^FGc
lME)?LOI
} /M*a,o
zdEPDdB
//线程睡眠 A6pjRxg
public static void sleep(int nSecond) y:vxE8$Q
{ DANw1_X\
try{ P b]3&!a
Thread.sleep(nSecond); pmFk50`
} +ke1Cn'[
catch(Exception e) *mMEl]+
{ =pznu+,
e.printStackTrace (); pKjoi{ Z
} \a=D
} DVkB$2]
v^_mFp-}\
//日志 {|yob4N
public static void log(String sMsg) aKd+CO:
{ yin'vgQ
System.err.println(sMsg); ^-a8V'
} d'|,[p
viAMr"z
jOyvDY9\
public static void log(int sMsg) j$TwL;
{ ^_%kE%I
System.err.println(sMsg); j* *s^Sg
} vUnRi=:|
} !QT'L,_
PT5AA8F
gt7VxZ
/* ]Bm>-*@0N
**TestMethod.java W(Uu@^
*/ 4#'("#R
package NetFox; *k1<: @%e
H-xFiF
[F[K^xYTlg
public class TestMethod { 1<<kA:d
7]%Ypv$
%c1#lEC2xN
public TestMethod() S#-tOjU*
{ ///xx/weblogic60b2_win.exe F5 ]C{
try{ Z-B%'/.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); v*qQ?S
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); q;:6_Qr
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2EK%N'H
fileFetch.start(); $ A9%UhV
} f(eQ+0D
catch(Exception e){e.printStackTrace ();} pMJ1v
.y&QqxiE
rJo"fx
} /2m?15c+
Hku!bJ
i"j(b|?e
public static void main(String[] args) wM_ 6{
{ @Fpb-Qd"
new TestMethod(); kGUJ9Du
} vw)7 !/#
} u?[ q=0.J7
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