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)); Ddl% V7
} D@(M+u9/%
for(int i=0;i<nEndPos.length-1;i++) YV3TxvXMR
{ 88np/jvC{
nEndPos = nStartPos[i+1]; zj$_iB`9
} h>^jq{yu
nEndPos[nEndPos.length-1] = nFileLength; 8 1KG1i)
} K?Xo3W%K
} t2-nCRXEP
vzyI::f?
?` eYWZ">
//启动子线程 @Wx`l) b
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; F%_,]^ n[
for(int i=0;i<nStartPos.length;i++) TCKI
{ ,F?~'-K
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W#Hv~1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gKs/T'PW
nStartPos,nEndPos,i); AeY$.b
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F'UguC">
fileSplitterFetch.start(); zA'gb'MmW
} cdJ`Gk
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @RoRNat
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Xc9p;B>^Ts
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", CDnR
nEndPos = " + nFileLength); @!&Jgg53G
// fileSplitterFetch[nPos.length-1].start(); K?FX<PT
A1|7(Sow
uzVG q!'H
//等待子线程结束 #GY&$8.u*
//int count = 0; -lP )
//是否结束while循环 :?$Sb8OuIL
boolean breakWhile = false; \=EY@*=
*< $c =
^z*):e
while(!bStop) C)J_lI{^
{ (pT(&/\8
write_nPos(); z@Z_] h
Utility.sleep(500); ]{Mci]H6T
breakWhile = true; Fi?32e4KI5
]F"(OWW
TXd5v#_vo
for(int i=0;i<nStartPos.length;i++) daA47`+d
{ t?]\M&i&
if(!fileSplitterFetch.bDownOver) IDGQIg
{ O?nPxa<
breakWhile = false; >bX-!<S
break; !"`@sd~
} 93E,
} Ism^hyL
if(breakWhile) (C-,ljY
break; [):{5hMA
:rz9M@7
QMXD9H0{
//count++; T:K"
//if(count>4) ;mf4U85
// siteStop(); ;Pol#0_(
} yCF"Z/.
QHHW(InG<
zuC58B
System.err.println("文件下载结束！"); /<3;0~#){
} o}9M`[
catch(Exception e){e.printStackTrace ();} 0t#NMW
} Hv8SYQ|
'GEBxNH:
zY7*[!c2
//获得文件长度 fOa6,
public long getFileSize() U0NOU#
{ W4)kkJ
int nFileLength = -1; k1ipvKxp:8
try{ P'a0CE%
URL url = new URL(siteInfoBean.getSSiteURL()); xN#bzma
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dO>k5!ge|:
httpConnection.setRequestProperty("User-Agent","NetFox"); ZWf-X
iBG`43;
j2RRSz&9
int responseCode=httpConnection.getResponseCode(); >;&Gz-lm
if(responseCode>=400) Sg-g^dIN1
{ 6OfdD.y
processErrorCode(responseCode); OJv}kwV
return -2; //-2 represent access is error -'I _*fu
} xj0cgK|!
m!rwG(
4rI:1yGt@
String sHeader; J&A;#<qY
lkV6qIj
HH"$#T^-
for(int i=1;;i++) M6J/mOVx5
{ ./#e1m?.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); fJX\'Rc\
//Utility.log(in.readLine()); -@rxiC:Q
sHeader=httpConnection.getHeaderFieldKey(i); sT)6nV
if(sHeader!=null) }ppVR$7]0
{ DC&A1I&
if(sHeader.equals("Content-Length")) JxjP@nr
{ 'nMApPl
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8O;Vl
break; 4py(R-8\
} H6_xwuw:
} DMB"Y,
else cFLd)mt/
break; Mec{_jiH&D
} F<5nGx cC
} CD}Ns
catch(IOException e){e.printStackTrace ();} i`+B4I8[
catch(Exception e){e.printStackTrace ();} 6_*!|g
Y&s2C%jT
yIOLs}!SF
Utility.log(nFileLength); _ENuwBYW-
6^sHgYR
co/7lsW
return nFileLength; Ivsb<qzG
} DF'8GF&Rp
\OcMiuw
~n6[$WjZA
//保存下载信息（文件指针位置） =D].`
private void write_nPos() %fv)7 CRM
{ W<NmsG})_g
try{ Ib1e#M3
output = new DataOutputStream(new FileOutputStream(tmpFile)); rs:Q%V ^
output.writeInt(nStartPos.length); IZ8y}2
for(int i=0;i<nStartPos.length;i++) RlsVC_H\
{ Zm(dY*z5:J
// output.writeLong(nPos); RZO5=L9E
output.writeLong(fileSplitterFetch.nStartPos); G AQ 'Ti1!
output.writeLong(fileSplitterFetch.nEndPos); c&f y{}10
} YUscz!rM
output.close(); ID4~Gn
} 4<.O+hS
catch(IOException e){e.printStackTrace ();} [9V]On
catch(Exception e){e.printStackTrace ();} }>&KUl
} JRO$<
m_*R.a
7yI`e*EOD
//读取保存的下载信息（文件指针位置） |y"jZT6R}t
private void read_nPos() aI(>]sWJ
{ O"*`'D|hK
try{ v7IzDz6gF
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5j{Np,K
int nCount = input.readInt(); :.iyR
nStartPos = new long[nCount]; %6ub3PLw8
nEndPos = new long[nCount]; Sdd9Dv?!
for(int i=0;i<nStartPos.length;i++) wqD5d
{ ?t rV72D
nStartPos = input.readLong(); Pl+xH%U+?
nEndPos = input.readLong(); )NT5yF,m
} t`G)b&3_O
input.close(); gUVn;_
} 7zDiHac
catch(IOException e){e.printStackTrace ();} 4_LQ?U>$
catch(Exception e){e.printStackTrace ();} *8)2iv4[
} w#(RW7":F
],lV}Mlg*
N[Sb#w`[/
private void processErrorCode(int nErrorCode) )%Ru#}1X6
{ q0O&UE)6Y
System.err.println("Error Code : " + nErrorCode); 8]< f$3.
} |dmh
otr>3a*'
0^~\COa
//停止文件下载 $h28(K%
public void siteStop() Veji^-0E
{ }/e`v6
bStop = true; NY.k.
for(int i=0;i<nStartPos.length;i++) .L;@=Yg)
fileSplitterFetch.splitterStop(); |n6Eg9
@5<CXTdF9c
R,Oe$J<
} 2 x4=
} o6}n8U}bk
//负责部分文件的抓取 D>sYPrf
**FileSplitterFetch.java $Ui&D I
*/ AQ{zx1^2>K
package NetFox; >V;,#5F_
\#dl6:"
Z=+03
import java.io.*; IFuZ]CBz
import java.net.*; u oVNK
%_gho
r;qzo.
public class FileSplitterFetch extends Thread { tRfm+hqRZ
}zMf7<C
8_we: 9A
String sURL; //File URL j"7 JLe*
long nStartPos; //File Snippet Start Position ;IZ?19Q
long nEndPos; //File Snippet End Position jO'|mGUM
int nThreadID; //Thread's ID F^kwdS
boolean bDownOver = false; //Downing is over 7_\Mwy{P
boolean bStop = false; //Stop identical Fhj8lVvk
FileAccessI fileAccessI = null; //File Access interface \2X$C#8E
HKmcQM
fCUT[d+H
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException BzbDZV
{ ,Og4 ?fS
this.sURL = sURL; rVryt<2:@r
this.nStartPos = nStart; *\XH+/]+
this.nEndPos = nEnd; z&+ zl6
nThreadID = id; YD[H
fileAccessI = new FileAccessI(sName,nStartPos);//定位 3h=8"lRc
} F@vbSFv)/
ffcLuXa
(Mt5P
public void run() y?z\L
{ pP/@
while(nStartPos < nEndPos && !bStop) --k:a$Nt
{ 2WCLS{@'
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\e:d)^cbh
try{ LtKB v4
URL url = new URL(sURL); lAASV{s{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kU*{4G|6
httpConnection.setRequestProperty("User-Agent","NetFox"); UQ8bN I7
String sProperty = "bytes="+nStartPos+"-"; xHkxc}h
httpConnection.setRequestProperty("RANGE",sProperty); \7 a4uc
Utility.log(sProperty); lF4u{B9DM
D-ADv3E,
G*n2Ii
InputStream input = httpConnection.getInputStream(); _N#&psQzw
//logResponseHead(httpConnection); hU {-a`
9'KonW
T{Zwm!s
byte[] b = new byte[1024]; }vh Za p^
int nRead; BGWAh2w6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3'eG;<F
{ v[,Src
nStartPos += fileAccessI.write(b,0,nRead); H%i>L?J2/
//if(nThreadID == 1) _6LoVS
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pj{\T?(
} v,1F--v
*Xr$/N
l(kr'x
Utility.log("Thread " + nThreadID + " is over!"); u<Xog$esu
bDownOver = true; 8tc*.H{^+
//nPos = fileAccessI.write (b,0,nRead); ?y%t}C\W
} Re[:qLa]
catch(Exception e){e.printStackTrace ();} 7TWNB{ K_
} bXdY\&fE
} *gqSWQ
i/qTFQst _
!]b@RUU
//打印回应的头信息 `a4 $lyZ
public void logResponseHead(HttpURLConnection con) %_f;G+fK\p
{ ef]B9J~h
for(int i=1;;i++) ZF{~ih*^u
{ Z9 w:&oa@
String header=con.getHeaderFieldKey(i); aG27%(@
if(header!=null) V2 `> ]/|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); TQ'E5^
Utility.log(header+" : "+con.getHeaderField(header)); #Z9L_gDp
else &8?`<
break; 8LrK94
} @$U e$
} b X,Siz:F
JP=ZUu
J!p<oW)a!
public void splitterStop() bkv/I{C>?
{ ?q$P>guH6-
bStop = true; 3% vis\~^
} w|Qd`
c> ~:dcy
;z>p8N
} m|4LbWz
a$}6:E
V SAafux
/* rsxRk7s@
**FileAccess.java DY3:#X`4
*//文件访问(定位，写) 04JT@s"o
package NetFox; J(9=T<%T
import java.io.*; ^k72{ 3N(
GX38~pq
O@,i1ha%
public class FileAccessI implements Serializable{ &?T${*~
x0G>ktWq<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 v5 Y)al@
RandomAccessFile oSavedFile; `:5,e/5,
long nPos; l l:jsm
(02g#A`
uUS)#qM|
public FileAccessI() throws IOException [%~NM/xu<
{ q/'MS[C
this("",0); }td6fj_{
} 78w4IICk
o*_g$
UK:M:9
public FileAccessI(String sName,long nPos) throws IOException 8IOj[&%0
{ .tp=T
oSavedFile = new RandomAccessFile(sName,"rw"); (`mOB6j
this.nPos = nPos; Xz* tbW#
oSavedFile.seek(nPos); HA\A$>
} :SeLkQC
V"g~q?@F
yu_gNro L
public synchronized int write(byte[] b,int nStart,int nLen) P:a*t[+
{ P^;WB*V
int n = -1; ._(z~3s
try{ $68 XZCx
oSavedFile.write(b,nStart,nLen); 6#-Z@fz%
n = nLen; !Iko0#4i
} T~|PU{
catch(IOException e) 9BurjG1k?
{ 't ;/,+:V
e.printStackTrace (); oHRbAE^
} vT}pbOTh
=ZrjK=K
1W7 iip,
return n; ,gx$U@0Z
} KK .cDAR
E = ^-Z
DW4MA<UQ
} {cX7<7N
`F@f?*s:
N~0$x,bR
/* @Zh8 QI+
**SiteInfoBean.java 7TR'zW2W
*/ Z#[>N,P
package NetFox; R+x%r&L5F
0-lPhnrp
Je@p5(f
public class SiteInfoBean { Hv+:fr"
s+Cl
=7H.F:BBG
private String sSiteURL; //Site's URL 5Bzuj`
private String sFilePath; //Saved File's Path |)*m[_1
private String sFileName; //Saved File's Name sCL/pb]
private int nSplitter; //Count of Splited Downloading File 0FN~$+t)H
b^@`uDb6
}NR`81
public SiteInfoBean() zl,bMtQ
{//nSplitter的缺省值为5 Vl&+/-V
//default value of nSplitter is 5 ?%_]rr9
this("","","",5); 5IwX\
} \>w@=bq26
hVROzGZk
X*43!\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) aEV|>K=6Y'
{ %'$cH$%~J
sSiteURL= sURL; cob9hj#&7
sFilePath = sPath; _+0uju?o}
sFileName = sName; G}Q}H*
this.nSplitter = nSpiltter; {[H4G,QK
hXj* {vT
:XNK-A W
} QYFN:XZ
}7f 1(#{7
oaH+c9v
public String getSSiteURL() KE&InTM/j
{ Cnb[t[hk+j
return sSiteURL; :*^(OnIe
} 'd~, o[x
s\F EA"w/
h7Shl<f
public void setSSiteURL(String value) ]JhDRJ\
{ FE^?U%:u@
sSiteURL = value; >@q2FSMf
} }V93~>
:BC<+T=
2J>A;x_?
public String getSFilePath() 3P=Eb!qtdD
{ {HE.mHy
return sFilePath; 'Sb6 w+
} s%0[DO3NV
K!$\REs
FW6E)df
public void setSFilePath(String value) &~D.")Dz
{ k~W;TCJs
sFilePath = value; o i,g
} $bM#\2'
yF [@W<
%te'J G<
public String getSFileName() {H"=PYR
{ UJyiRP:#]>
return sFileName; 4I]/
} ~ 33@H
*N&^bF"SF
=*U%j
public void setSFileName(String value) V< 9em7
{ FB^dp}
sFileName = value; 6:7:NIl:
} y:(C=*^<t
Qnu&GBM
wft:eQ
public int getNSplitter() [fJFH^&?hr
{ -`ys pE0?
return nSplitter; d$G%F$BTs
} eyl) uR
NVM2\fs
E6KBpQcd[
public void setNSplitter(int nCount) J*W;{Vty
{ P.2.Ge|
nSplitter = nCount; u/c~PxC
} !h~#L"z
} )jQe K
kgI.kT(=
]Rys=.!
/* nR|uAw
**Utility.java MRY)m@*+6
*/ cDh4@V
package NetFox; :."n@sA@
`^4>^
d)J] Y=j
public class Utility { sMe~C>RD
K=^_Ndz
9#$V1(}?
public Utility() QH?2v
{ l`w|o
@'| 6lG
yl;$#aZB
} a(t<eN>b!
~a0}
//线程睡眠 '~x_
public static void sleep(int nSecond) /JY ph^3][
{ K&~#@I;
try{ =.2cZwxX$
Thread.sleep(nSecond); ,IX4Zo"a
} u$`x]K=Zsm
catch(Exception e) F#C6.`B
{ W&q5cz
e.printStackTrace (); .6-o?=5
} ` vmk
} (DaP~*c3cC
vWfef~}~
//日志 {*P7)
public static void log(String sMsg) YyBq+6nq5
{ IXk'?9
System.err.println(sMsg); /P:WQ*
} )ZT0zIG
thboHPml{
o_+Qer=O6
public static void log(int sMsg) d:WhP_rK9
{ -bX.4+U
System.err.println(sMsg); dM;WG;8e
} _=$!T;}lE
} l e/#J
@x>2|`65Y
~G^doj3|+
/* ,]N%(>ot
**TestMethod.java 'cc4Y~0s
*/ }^bL'
package NetFox; B{i;+[ase
u5B/Em7,0
o5A_j?t
public class TestMethod { 2gI_*fG1
xa^HU~
H<Taf%JT
public TestMethod() ee?ZkU#@
{ ///xx/weblogic60b2_win.exe xR%ayT.
try{ oD2;Tdk
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -H;y_^2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =_:L wmI
SiteFileFetch fileFetch = new SiteFileFetch(bean); h\ek2K
fileFetch.start(); lR3^&d72?
} -k{R<L
catch(Exception e){e.printStackTrace ();} D6:J*F&?
=5eDT~=2{U
NX",e=
} BC[d={_-
W"@lFUi
AWNd(B2o
public static void main(String[] args) ;z=C]kI6M
{ `3n*4Lz
new TestMethod(); 1"6k5wrIA
} Kn\(Xd.>
} 0)44*T
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