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)); JdK'~-L
} S#^2k!(|G
for(int i=0;i<nEndPos.length-1;i++) 5OR2\h!XZt
{ <?&Y_
nEndPos = nStartPos[i+1]; ,Hzz:ce
} 2lc
nEndPos[nEndPos.length-1] = nFileLength; (qbL=R"
} ;K$ !c5
} i0TbsoKh:
(\8~W*ej"
RXD*;B$v
//启动子线程 X>la!}sV
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; UD!-.I]
for(int i=0;i<nStartPos.length;i++) t4P`#,:8
{ xk:=.Qqh
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W0 n?S "
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "PD^]m
nStartPos,nEndPos,i); kF@Z4MB}yr
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VL?sfG0
fileSplitterFetch.start(); Mjon++>Z
} wwuM!Z+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k Xg&}n7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 44x+2@&1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", lM|}K-2
nEndPos = " + nFileLength); @fc-[pv
// fileSplitterFetch[nPos.length-1].start(); \}n\cUy-
g!\H^d4
w!eY)p<
//等待子线程结束 (6crWw{3
//int count = 0; #>ob1b|
//是否结束while循环 81}JX
boolean breakWhile = false; (B^rW,V[R
M/mm2?4
7@1GSO:Yf
while(!bStop) ]i:_^z)R
{ [2P6XoI#
write_nPos(); Q;xJ/4 Z"
Utility.sleep(500); L[cP2X]NQ
breakWhile = true; o}p^q:T*
rHa*WA;TE
z@21Z`,
for(int i=0;i<nStartPos.length;i++) L+X:M/)
{ )vsX (/WU
if(!fileSplitterFetch.bDownOver) <0!O'" "J
{ YctWSfh
breakWhile = false; SYd6D@^2j
break; xjy(f~'
} 8-PHW,1@a3
} ,gdud[&|;
if(breakWhile) rQD^O4j R
break; OfK>-8
idNra#
Rz#q68
//count++; k.ttrKy<q/
//if(count>4) Q@ Ze+IhK`
// siteStop(); X5tx(}j
} srQGqE~
%xv*#.<Vj
eev-";c
System.err.println("文件下载结束！"); B2,c_[UZ.
} q|g>;_
catch(Exception e){e.printStackTrace ();} 8CUlE-R5
} 3oOr*N3R
-.OZ
3c=>;g
//获得文件长度 we/sv9v}n
public long getFileSize() cSTF$62E
{ (6*
int nFileLength = -1; yu>o7ie+;Y
try{ !$hi:3{U,
URL url = new URL(siteInfoBean.getSSiteURL()); *>h|<|T'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P?ms^
httpConnection.setRequestProperty("User-Agent","NetFox"); 4Ql9VM%y
#:NY9.\o
EeR}34
int responseCode=httpConnection.getResponseCode(); =<%[P9y
if(responseCode>=400) 4nrn Npf`b
{ EO`eg]
processErrorCode(responseCode); ?2%;VKN4
return -2; //-2 represent access is error U,K=(I7OBX
} )|=4H>?%
}/lyrjV
P-/"sD
String sHeader; bXi!_'z$
}P'c8$
v!W{j&N
for(int i=1;;i++) PX*}.L *x
{ .1+I8qj
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); v5\5:b{/
//Utility.log(in.readLine()); E/zclD5S
sHeader=httpConnection.getHeaderFieldKey(i); 6f:uAFwG
if(sHeader!=null) );zLgNx,
{ X'88W-
if(sHeader.equals("Content-Length")) DNr*|A2<
{ <aLS4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); oOHY+'V
break; 7`f%?xVn0
} GC~nr-O
} >xXC=z+g]
else KM+[1Ze$
break; %P7qA
} |\W53,n9
} |R2p^!m
catch(IOException e){e.printStackTrace ();} pm=m~
catch(Exception e){e.printStackTrace ();} oY+p;&H
N%?R(
TuEM
Utility.log(nFileLength); WvZt~x&2
c5_/i7
iu?gZVyka
return nFileLength; {_mVfFG
} shR|
UwxszEHC
}<YU4EW
//保存下载信息（文件指针位置） P{x6e/
private void write_nPos() %Zp|1J'"
{ \Si p
try{ ?qb35
output = new DataOutputStream(new FileOutputStream(tmpFile)); \,fa"^8
output.writeInt(nStartPos.length); ~yt7L,OQ
for(int i=0;i<nStartPos.length;i++) `^] D;RfE
{ @C<ofg3E
// output.writeLong(nPos); &)jq3
output.writeLong(fileSplitterFetch.nStartPos); \1SC:gN*#
output.writeLong(fileSplitterFetch.nEndPos); i),bAU!+m
} 'J$@~P
output.close(); 9GRQ^E
} j XH9Pq4
catch(IOException e){e.printStackTrace ();} +4 h!;i
catch(Exception e){e.printStackTrace ();} 9;'#,b*(
} v2I? 5?j
v<t?t<|J
e_|Z&
//读取保存的下载信息（文件指针位置） 4i PVpro
private void read_nPos() ~8yh,U
{ tXqX[Td`0g
try{ =7JSJ98
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); F(#?-MCs
int nCount = input.readInt(); #%2d;V
nStartPos = new long[nCount]; cS'{h
nEndPos = new long[nCount]; zPxR=0|
for(int i=0;i<nStartPos.length;i++) W7Y@]QMX
{ B;?)X&n|X
nStartPos = input.readLong(); /y$Fw9R;
nEndPos = input.readLong(); b*.aaOb
} 6UqAs<c9
input.close(); vJaWHC$q
} x(cv}#}S8
catch(IOException e){e.printStackTrace ();} i%JJ+9N
catch(Exception e){e.printStackTrace ();} Ix6\5}.c9
} 0ki- /{;
XPU>} 4{
|1"&[ .
private void processErrorCode(int nErrorCode) /OWwC%tM/
{ xnt)1Q
System.err.println("Error Code : " + nErrorCode); oOaFA+0x
} |?#JCG
A[8m3L#k
oX8EY l
//停止文件下载 tj'~RQvO
public void siteStop() \yu7,v
{ 6^WNwe\
bStop = true; bY2R/FNL=
for(int i=0;i<nStartPos.length;i++) vUVFW'-
fileSplitterFetch.splitterStop(); y^,QM[&
'.1P\>x!]
4"k&9+>
} ~f(5l.
} IJ&Lk=2E]
//负责部分文件的抓取 W-l+%T!
**FileSplitterFetch.java L7Hv)
*/ v@soS1V!
package NetFox; o0]YDX@T
= V2Rq(jH
O-X(8<~H=
import java.io.*; Xg96I:r'p
import java.net.*; $Yt|XT+!&
0M"n
7;o:r$08&}
public class FileSplitterFetch extends Thread { S)rr
60vmjmXl
E<Zf!!3
String sURL; //File URL jkx>o?s)z
long nStartPos; //File Snippet Start Position jel:oy|_
long nEndPos; //File Snippet End Position Ig t*8px
int nThreadID; //Thread's ID X'jyR:ut#
boolean bDownOver = false; //Downing is over <@"rI>=
boolean bStop = false; //Stop identical %*}rLn"?
FileAccessI fileAccessI = null; //File Access interface Yr/$92(
Jgv Mx
7%i'F=LzT
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException hqvhnqQk
{ X7huc*
this.sURL = sURL; $C;i}q#
this.nStartPos = nStart; b^Z2Vf:k]
this.nEndPos = nEnd; ?E"192,z@
nThreadID = id; D[/fs`XES
fileAccessI = new FileAccessI(sName,nStartPos);//定位 'EiCTl
} L@{'J
s|e.mZk/
Vo@7G@7K(
public void run() U-9Aq
{ h(HpeN%`#
while(nStartPos < nEndPos && !bStop) !xfDWbvHV
{ #\w N2`" W
.Qx5,)@9
1H-Y3G>jN
try{ U L $!
URL url = new URL(sURL); Q38+`EhLA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ng3ZK
httpConnection.setRequestProperty("User-Agent","NetFox"); VKDOM0{V
String sProperty = "bytes="+nStartPos+"-"; P}}G9^
httpConnection.setRequestProperty("RANGE",sProperty); 9?H$0xZV
Utility.log(sProperty); SYYx>1;8`
rJpr;QKf%
\Nt 5TG_
InputStream input = httpConnection.getInputStream(); K9#kdo1 2
//logResponseHead(httpConnection); Nn[*ox#i
|O_JUl
]ub"OsXC
byte[] b = new byte[1024]; C8|V?bL
int nRead; X\h.@+f=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |@X^_L.!
{ -xHR6
nStartPos += fileAccessI.write(b,0,nRead); ;DuVb2~+
//if(nThreadID == 1) '#f<wfn
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Iw`tbN L[
} .D 4G;=Q
x"Ky_P~
8M*+ |
Utility.log("Thread " + nThreadID + " is over!"); ~a([e\~
bDownOver = true; ed,A'S=d
//nPos = fileAccessI.write (b,0,nRead); T/3LJGnY
} vTK%4=|1}!
catch(Exception e){e.printStackTrace ();} }ssV"5M
} >[;W~*
} -wXeue},>
Mp`$1Ksn
~.W]x~X$
//打印回应的头信息 r'OqG^6JFN
public void logResponseHead(HttpURLConnection con) N:<$]x>
{ '5BD%#[
for(int i=1;;i++) rtuaU=U
{ y|6n:<o
String header=con.getHeaderFieldKey(i); .G[/4h :.
if(header!=null) G?$@6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ab@G^SLX
Utility.log(header+" : "+con.getHeaderField(header)); eM<N?9s
else kkq1:\pZ]a
break; ab2FK
} ]bY|>q
} e'K~WNT
,m=G9QcN
EB[T 5{
public void splitterStop() N(7XILC
{ Z\nDR|3
bStop = true; A9.TRKb=8
} ^O_Z5NbC3
spV7\Gs.@
]I\GnDJ^
} =P(*j7=
f!x9%
7l53&,s
/* L!cOg8Z
**FileAccess.java hTtn /j
*//文件访问(定位，写) JY"jj}H]|
package NetFox; ,.<mj !YE
import java.io.*; [./FzlAs
A<+Dx
pp@ Owpb
public class FileAccessI implements Serializable{ ;:6\w!fc
|`LH|6/
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 j$)ogGu
RandomAccessFile oSavedFile; !/}3/iU
long nPos; "#~>q(4^
w5%Yi{
" @D
public FileAccessI() throws IOException %zcA|SefP
{ 8gS7$ EH'
this("",0); >of34C"DI
} zgwez$
$:~;U xh=
\l59/ZFan
public FileAccessI(String sName,long nPos) throws IOException uN`/&_$c
{ &*v\t\]
oSavedFile = new RandomAccessFile(sName,"rw"); &en. m>9,
this.nPos = nPos; O&l4/RtQ\)
oSavedFile.seek(nPos); TDH^x1P
} O%EA,5U.
sycAAmH<
yqx5_}
public synchronized int write(byte[] b,int nStart,int nLen) `;UWq{"
{ pQiC#4b
int n = -1; ]DNPG"
try{ -ZaeX]^&Q\
oSavedFile.write(b,nStart,nLen); @ZJL]TO
n = nLen; ?4b0\ -
} -Uo11'{
catch(IOException e) &D<R;>iI
{ `g]
e.printStackTrace (); G=:/v
} yNvAT>H
QL7b<xDQC*
4m0^ N
return n; +hN>Q$E
} c~R'`Q
Xd(^7~i
cyl%p$
} ,';|CGI cP
{+J{t\`
<X)\P}"L4
/* /*#o1W?wQZ
**SiteInfoBean.java ;5tOQ&p%v
*/ Jq/itsg
package NetFox; 4zyQ"?A~
1iF=~@Nz_
Pe_O(
public class SiteInfoBean { ,jY:@<n
yT7$6x
k'o[iKlu
private String sSiteURL; //Site's URL (ghI$oH
private String sFilePath; //Saved File's Path Lwl1ta-
private String sFileName; //Saved File's Name -EiTP:A
private int nSplitter; //Count of Splited Downloading File Dj\nsc@e3
_WEJ,0*#'
=.3#l@E!C
public SiteInfoBean() 'n'>+W:
{//nSplitter的缺省值为5 `]KX`xGK
//default value of nSplitter is 5 h3@tZL#g
this("","","",5); eAlOMSL\
} &E&~9"^hQL
d,^O[9UWo
!UoA6C:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) nm5DNpHk
{ ;I4vPh5Q
sSiteURL= sURL; e8vy29\S
sFilePath = sPath; KuP#i]Na
sFileName = sName; \GL] I.
this.nSplitter = nSpiltter; 5Y *4a%"
6|eqQ+(A
a`'>VCg
} ozRO:*51
+YvF+E
#tV1?q
public String getSSiteURL() M/W"M9u
{ o|@0.H|
return sSiteURL; m!xvWqY+
} s;vt2>;q+e
=Kkqk
AX v q~XE
public void setSSiteURL(String value) uyYV_Q0~;
{ j.&dHtp
sSiteURL = value; t(3f} ?
} 2_wue49-l
e4z~
D>5)',D8xi
public String getSFilePath() $'V^_|EL7
{ _pTcSp3
return sFilePath; <odi>!ViH
} Al^tM0T^
uY5|Nmiu
)V1xL_hx/
public void setSFilePath(String value) . Vb|le(7
{ 9)VAEyv
sFilePath = value; 3RtVFDIZA"
} %E_Y4Oe1
+@rFbsyJ.
5=?P6I_$G
public String getSFileName() $4{sPHi)I
{ m \)B=H!bz
return sFileName; xrg"/?84
} "B3jq^
AY52j
IS]A<}j/-
public void setSFileName(String value) HUx`RX0>
{ b=EI?XwJ
sFileName = value; !P{ /;Q
} |Y!^E %*
)Eozo4~
+Csb8
public int getNSplitter() JQKXbsXS
{ F7<mm7BGZ
return nSplitter; }eLApFHEDg
} GKoYT{6
|XB<vj07G
ql@2<V{
public void setNSplitter(int nCount) d#T5=5#
{ J,W$\V]p
nSplitter = nCount; 9Kd=GL_
} 8ae`V!5
} li%@HdA!
0cmd +`
/l7 %x.
/* LgF?1?
**Utility.java QP'sS*saJ
*/ ?6_]^:s
package NetFox; &oMEz 0
i431mpMa
T:Cq}4k<
public class Utility { &oG>Rqkm
G u`xJ
ya2sS9^T[
public Utility() 5~h)pt47
{ kqeEm{I
c^w^'<
4pL'c@'
} :P-H8*n""
U '{PpZ
//线程睡眠 &0T.o,&y
public static void sleep(int nSecond) x@Gg fH<l
{ M5VW1Ns
try{ ^KbR@Ah
Thread.sleep(nSecond); RFbf2s\t
} ;}Jv4Z
catch(Exception e) ]C^ #)7
{ ,[ 2N3iH
e.printStackTrace (); GSRf/::I}4
} M %,\2!$
} q;9X8 _
p.:|Z-W$
//日志 RZxh"lIo
public static void log(String sMsg) a?W5~?\9
{ eztK`_n
System.err.println(sMsg); +^9^)Ur|
} :?f+*
QP(d77n
_gVihu
public static void log(int sMsg) ;.jj>1=Tnl
{ R_j.k3r4d
System.err.println(sMsg); yM 7{v$X0
} o135Xh$_>'
} i5r<CxS
rTR$\ [C
\Hb!<mrp
/* ;I5P<7VW
**TestMethod.java -+){;,
*/ {EZR}N
package NetFox; +\+j/sa
NzZ(Nz5
p{oz}}
public class TestMethod { pq0Z<b;2
$x}R2
{ 5r]G
public TestMethod() /'8%=$2Kw
{ ///xx/weblogic60b2_win.exe /[ m7~B]QE
try{ qD%88c)g
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); n_{&dVE
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); O\7x+^.
SiteFileFetch fileFetch = new SiteFileFetch(bean); Q7u|^Gu,5
fileFetch.start(); #c:@oe4v
} =H7p&DhD[
catch(Exception e){e.printStackTrace ();} OR&pGoW
4j;IyQDvM
qdQ4%,E[
} ?n<F?~
"6]oi*_8
G739Ne[gL
public static void main(String[] args) UZ/LR
{ D*@'%<?
new TestMethod(); %x#S?GMV<
} SkV pZh
} vgc~%k62c
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