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)); pbAQf3
} YS/{q~$t
for(int i=0;i<nEndPos.length-1;i++) w0VJt<e*
{ Gv3a<Knn4
nEndPos = nStartPos[i+1]; P|c79
} ]w! x
nEndPos[nEndPos.length-1] = nFileLength; 4RJ8 2yq-
} fokOjTE
} par $0z/
91`biVZfA
G+=&\+{#4
//启动子线程 8la.N*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; E WOn"
for(int i=0;i<nStartPos.length;i++) &QLCij5:
{ hG; NJx-=R
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F< Qjoaz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), wvsTP32]
nStartPos,nEndPos,i); %<:?{<~wH9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [sbC6(z
fileSplitterFetch.start(); :,6dW?mun6
} bvs0y7M='
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,??xW{*|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); r(0I>|u
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Pa%XLn'5
nEndPos = " + nFileLength); qFt%{~a S
// fileSplitterFetch[nPos.length-1].start(); }yC ve
nSmYa7
tk2B\}6
//等待子线程结束 =^O84Cp 6
//int count = 0; 3]M YHb
//是否结束while循环 Hk(w\
boolean breakWhile = false; &EV|knW
*ofK|r
qqLmjDv
while(!bStop) ok2$ p
{ 'R99kL/.N
write_nPos(); s>E4.0[I%
Utility.sleep(500); G{$9e}#
breakWhile = true; t&eY+3y,T
4f'WF5S/}8
\^w=T*
for(int i=0;i<nStartPos.length;i++) Ds$FO}KD{
{ }|&M@Up
if(!fileSplitterFetch.bDownOver) 78Nli/U
{ i=]IUjx<
breakWhile = false; CSR6
break; a:7"F{D91
} ,`B*rCOa
} >{$;O
if(breakWhile) &(IL`%
break; :Dw;RcZQ
JPS L-j
S\MD]>4
//count++; O"nY4
//if(count>4) LX!16a@SxA
// siteStop(); \bZbz/+D
} M +~guTh
o#4Wn'E
VEd\*
System.err.println("文件下载结束！"); LPvyfD;Zy
} *.~hn5Y|?
catch(Exception e){e.printStackTrace ();} av&dGsFP
} 9Or3X/:o
`3*>tq
w1h07_u;v
//获得文件长度 *Iyv${
public long getFileSize() Oh5(8.<y
{ TJ ;4QL
int nFileLength = -1; k;#$Oxa>t=
try{ AW!|xA6'`:
URL url = new URL(siteInfoBean.getSSiteURL()); L_=J(H|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >rB7ms/@E
httpConnection.setRequestProperty("User-Agent","NetFox"); f8B*D4R}
2u~0B +)K/
UW. F1)
int responseCode=httpConnection.getResponseCode(); N|WnUlf]:
if(responseCode>=400) x{&0:|bCs6
{ P)tXU
processErrorCode(responseCode); #B&D
return -2; //-2 represent access is error 72@8M
} {uDL"~^\
ak;fCx&
;yx+BaG~?
String sHeader; cJGA5m/{I
-~p@o1k0
(TDLT^
for(int i=1;;i++) 8n,i5>!d
{ Z"mpE+U*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h,\^Sb5AP
//Utility.log(in.readLine()); 7=6p
sHeader=httpConnection.getHeaderFieldKey(i); VQ$=F8ivG
if(sHeader!=null) I,l%6oPa
{ \4bma<~a
if(sHeader.equals("Content-Length")) iShB^
{ 0/#XUX 4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6jO*rseC
break; |&o1i~Y
} BB1'B-O
} LrsP4G
else `Z{; c
break; EN+WEMro
} ;#G>qo
} o`DBzC
catch(IOException e){e.printStackTrace ();} u> %r(
catch(Exception e){e.printStackTrace ();} !-|&
? Ls]k
3|[:8
Utility.log(nFileLength); ;KbnaUAS8
w(k7nGU]
X6N^<Z$
return nFileLength; 4O[5,
} tkR^dC
FJ!N)`[
&bRmr/D
//保存下载信息（文件指针位置） ^8 AV#a
private void write_nPos() "k"q)5c
{ _g0 qpa
try{ Ni"fV]'
output = new DataOutputStream(new FileOutputStream(tmpFile)); W7O%.xP
output.writeInt(nStartPos.length); \Nb6E&+
for(int i=0;i<nStartPos.length;i++) s3uT:Xw3rW
{ `g6ZhG:W
// output.writeLong(nPos); /?9e{,\s
output.writeLong(fileSplitterFetch.nStartPos); A&Ut:OiA
output.writeLong(fileSplitterFetch.nEndPos); 0d9rJv}~
} \@*cj8e
output.close(); RIC'JLWQ
} 9 /t}S6b{
catch(IOException e){e.printStackTrace ();} hh|'Uq3
catch(Exception e){e.printStackTrace ();} ZBJ.dK?Ky|
} [A yq%MA
P=KOw;bs
h7~&rWb
//读取保存的下载信息（文件指针位置） l9qq;hhGP,
private void read_nPos() dGQy=T:
{ q~;P^i<Y
try{ @Ys(j$U't
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Rdwr?:y(]
int nCount = input.readInt(); &rq7;X
nStartPos = new long[nCount]; 7`~h'(k
nEndPos = new long[nCount]; KG4~t=J`
for(int i=0;i<nStartPos.length;i++) !#f4t]FM`B
{ n)sK#C-VA
nStartPos = input.readLong(); z=?ainnKx
nEndPos = input.readLong(); l!~8
} ^X)U^Qd
input.close(); o5BOe1_Pw
} ~.VWrHC
catch(IOException e){e.printStackTrace ();} &.K8cphj
catch(Exception e){e.printStackTrace ();} jO3Q@N0_
} j8hb
rQ30)5^V|
:*/<eT_
private void processErrorCode(int nErrorCode) b3#c0GL
{ :>F:G%(DK
System.err.println("Error Code : " + nErrorCode); w^A8ZT0^7
} |jEKUTv,G
yXg783B|v
yJ/m21f
//停止文件下载 oT\B-lx
public void siteStop() ;}.jRmnJ
{ /+JCi6{sHS
bStop = true; ag:#82C
for(int i=0;i<nStartPos.length;i++) JBeC\ \QX
fileSplitterFetch.splitterStop(); f$*M;|c1c/
v?K XTc%Z
lU:z>gC
} i._d^lR\t
} K)_0ej~C
//负责部分文件的抓取 =y0!-y
**FileSplitterFetch.java U5dJ=G
*/ y!blp>V6
package NetFox; N95"dNZE
U87VaUr
[0m'a\YE9
import java.io.*; o:f=dBmoX
import java.net.*; h'MX{Wm.
}1:jM_H)k
feQ_dA q
public class FileSplitterFetch extends Thread { o!sxfJKl
k3sP,opacX
$Z.c9rY1
String sURL; //File URL unSF;S<
long nStartPos; //File Snippet Start Position Q\m"n^XN
long nEndPos; //File Snippet End Position &{Uaa
int nThreadID; //Thread's ID bxrByu~|1
boolean bDownOver = false; //Downing is over q/m}+v]
boolean bStop = false; //Stop identical RNl%n}
FileAccessI fileAccessI = null; //File Access interface nITr5$f
va~:oA
qW?^_
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Vn=J$Uv0
{ )Qw|)='-
this.sURL = sURL; ln3x1^!
this.nStartPos = nStart; (0Hhn2JA
this.nEndPos = nEnd; _L%/NXu,
nThreadID = id; 0:v7X)St
fileAccessI = new FileAccessI(sName,nStartPos);//定位 P:ys--$"
} T/-PSfbkj
o"7,CQye
:3Ty%W&&
public void run() {D1=TTr^
{ 7QQ3IepP
while(nStartPos < nEndPos && !bStop) bnB}VRal
{ +&(sZFW5o
b[e+(X
I/XVo2Ee
try{ <ywxz1i
URL url = new URL(sURL); TD!QqLW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FRs5 Pb1
httpConnection.setRequestProperty("User-Agent","NetFox"); d<`Z{"g NS
String sProperty = "bytes="+nStartPos+"-"; {3_M&$jN
httpConnection.setRequestProperty("RANGE",sProperty); dkG-Yz~
Utility.log(sProperty); ,i>5\Yl%
c6BaC@2
*5*d8;@>
InputStream input = httpConnection.getInputStream(); i]8zZRe
//logResponseHead(httpConnection); yK{;72
sAnStS=>
J[VQ6fD%
byte[] b = new byte[1024]; {BJ[h
int nRead; dRWp/3 }
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) W5J"#^kdF8
{ axXAy5
nStartPos += fileAccessI.write(b,0,nRead); SV6Np?U
//if(nThreadID == 1) +qzsC/y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MbYa6jrF
} iOjmj0
5OpK~f5
Zt[ PkBi
Utility.log("Thread " + nThreadID + " is over!"); )oAK)e
bDownOver = true; pf] sL/g
//nPos = fileAccessI.write (b,0,nRead); FjkE^o>
} >"zSW?
catch(Exception e){e.printStackTrace ();} s49AF
} w y:USS?
} pBK[j([
> {fX;l
o#%2N+w
//打印回应的头信息 xjR/K&[m
public void logResponseHead(HttpURLConnection con) L|!9%X0.
{ ZiVTc/b
for(int i=1;;i++) Ddt(*z /
{ (Q#A Br8
String header=con.getHeaderFieldKey(i); 89'nbg
if(header!=null) M#F;eK2pf
//responseHeaders.put(header,httpConnection.getHeaderField(header)); h7gH4L!'u
Utility.log(header+" : "+con.getHeaderField(header)); ;M@/AAZ
else 5:^dyF&sm{
break; MFE~bU(h
} Q'$aFl'NR
} zzq/%jki
?w3f;v
z'fGHiX7.0
public void splitterStop() t?YGGu^
{ olK%TM[Y
bStop = true; .hETqE`E
} b*?="%eE(
sNS!/
!{Y$5)Xh`]
} Hr96sN.R
"}Ya.
el+euOV
/* 7th&C,c&
**FileAccess.java ~3/>;[!
*//文件访问(定位，写) a/>={mbKi
package NetFox; urXM}^
import java.io.*; Z^h'&c#
'3%!Gi!g
pX6OhwkTK
public class FileAccessI implements Serializable{ d:<{!}BR3
~w4aA<2Uq
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9at7$Nq
RandomAccessFile oSavedFile; .+.Y`0
long nPos; r95$B6
-I\_v*nA
mIl^
public FileAccessI() throws IOException bLaD1rnGi
{ )oHIRsr
this("",0); Q0ev*MS9Z
} {[)J~kC+
V`@@ufU}
]2K>#sn-]
public FileAccessI(String sName,long nPos) throws IOException `,\WhJ?9
{ p]=8=pE<
oSavedFile = new RandomAccessFile(sName,"rw"); 9dy"Y~c
this.nPos = nPos; |l7e*$j
oSavedFile.seek(nPos); )h>Cp,|{
} [x-Z)Q.5
i"sVk8+o!
C.pNDpx-
public synchronized int write(byte[] b,int nStart,int nLen) "6Ly?'HK
{ G8akMd]2
int n = -1; $\m=-5 0-
try{ y~p7&^FeR
oSavedFile.write(b,nStart,nLen); F}i rCi47c
n = nLen; Hsx`P
} Z*s/%4On
catch(IOException e) hMi!H.EX.
{ f-4<W0%
e.printStackTrace (); T5W r;a
} IxgnZX4N
K6!`b( v#
BC!l)2
return n; f85j?Jm
} 1`B5pcuI
z\fD}`^8
|MTgKEsn
} uR@\/6!@
.^P^lQT]>
m!E36ce}
/* #r:J,D6*
**SiteInfoBean.java (VwS9:`
*/ \p [!@d^
package NetFox; _RY<-B
LdVGFlcXi
r")=Z1y
public class SiteInfoBean { 9r\8 !R
^ /:]HG
)p12SGR5
private String sSiteURL; //Site's URL =NyzX&H6
private String sFilePath; //Saved File's Path @oYTJd(v{
private String sFileName; //Saved File's Name >:Q:+R;3o
private int nSplitter; //Count of Splited Downloading File s( 2=E|
|~v($c
j!:U*}f
public SiteInfoBean() #@lr$^M
{//nSplitter的缺省值为5 M}/%t1^g:
//default value of nSplitter is 5 cGOE$nL
this("","","",5); <Hm:#<\
} =eTI@pN`
+`.%aJIi9
-+Quw2465^
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `C_#EU-
{ 98o;_tU'
sSiteURL= sURL; G?>~w[#mQR
sFilePath = sPath; /i DS#l\0
sFileName = sName; )k29mqa`
this.nSplitter = nSpiltter; kD MS7y<s
( 9dV%#G\
v`x~O+
} ^/Gjk
Mk,8v],-Tj
kDO6:sjR7
public String getSSiteURL() ]DC]=F.
{ Z2*hQ`eE
return sSiteURL; wrGd40
} ?R"5 .3
/x-Ja[kL
UkXc7D^jwm
public void setSSiteURL(String value) f_.1)O'83
{ $_)YrqSo~
sSiteURL = value; Y k~ i.p
} X] Tb4
`2r21rVntf
h/-7;Csv
public String getSFilePath() !dVcnK1
{ R>pa? tQgK
return sFilePath; \EB]J\x<
} h`3;^T
)-9|3`
uVOpg]8d
public void setSFilePath(String value) ZpI_/
{ _%i|*
sFilePath = value; ufEt"P-X.
} ']+H P9i$
,u~\$Az6
Wc`Vcn1
public String getSFileName() |a\s}M1
{ 3%|<U51
return sFileName; l*%voKZG
} 4Z]^v4vb
'*-X3p
=bv8W <#
public void setSFileName(String value) S$muV9z2=
{ mpr["C"l
sFileName = value; :GL|:
} 5\QNGRu"
-@^SiI:C
UxzwgVT
public int getNSplitter() ]e?*7T]
{ r OB\u|Pg
return nSplitter; YWq[)F@0G
} i1aS2gFi_
}zLe;1Tx
%$sWNn
public void setNSplitter(int nCount) pR\etXeLd
{ \I'A:~b)L
nSplitter = nCount; WYaDN:kZf
} 3UrqV`x \
} *'exvY~
?kS5=&<
cpE&Fba}"
/* wQ[2yq
**Utility.java !lu$WJ{M
*/ Z|wZyt$$
package NetFox; *+@/:$|U
7*[>e7:A
/I6?t=?<
public class Utility { hk,Q=};
?cg+RNI
If4YqBG
public Utility() M6DyOe<
{ G9VzVx#T#
CqrmdWN
cRU.
} ]/d2*#
T6phD8#
//线程睡眠 v8pUt\m"
public static void sleep(int nSecond) jl:O~UL6i
{ /9GqEQsfM
try{ c+4SGWmO
Thread.sleep(nSecond); ]$*N5Y
} NPS=?5p>
catch(Exception e) (G$m}ng
{ 4r5,kOFWb
e.printStackTrace (); z':>nw
} x!"!oJG^k
} *FG@Dts^&
_BW$?:)9
//日志 MX9q )(:
public static void log(String sMsg) *=;=VUu5
{ OpH9sBnA
System.err.println(sMsg); UdLC]
} G.oaDGy
E,C<ox4e
7Uj[0Awn
public static void log(int sMsg) jj$'DZk
{ x$s#';*
System.err.println(sMsg); _=}Y lR
} v3]q2*`G#
} E176O[(V=
d3n TJX
gNZ^TeT
/* 1p8E!c{}j
**TestMethod.java %FF S&vd
*/ 5#2vSq!H
package NetFox; u\t ;
C($`'~b
wbr"z7}
public class TestMethod { .3HC*E.e
PfuYT_p4s
0tsll1
public TestMethod() 4|:{apH
{ ///xx/weblogic60b2_win.exe W tzV|e,
try{ b]Z@zS<8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #lct"8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?W(wtp,o
SiteFileFetch fileFetch = new SiteFileFetch(bean); wh~~g qi9
fileFetch.start(); m?M(79u[
} VVe>}
catch(Exception e){e.printStackTrace ();} F;~ #\X
k)4|%
*dKA/.g
} j,G/[V
YJ75dXc&&
-k<.Q=]<t
public static void main(String[] args) @*2FG\c<
{ =6+BBD
new TestMethod(); G:@gO2(D
} 4&$G;?#W2
} Ws1<Jt3/."
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