http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); i-4L{T\K
} y,n.(?!*
for(int i=0;i<nEndPos.length-1;i++) xpuTh"ED
{ eA?|X|
nEndPos = nStartPos[i+1]; T7/DH
} eA Fp<2g
nEndPos[nEndPos.length-1] = nFileLength; x]%,?Vd?
} Gkfzb>_V]
} ~/aCzx~
j)iUg03>/4
\/Q~C!
//启动子线程 X#ha*u~U
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *x p_#
for(int i=0;i<nStartPos.length;i++) 0ZI}eZA j
{ y>u|3:z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7!Im|7Ty
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ttlMZLX{TJ
nStartPos,nEndPos,i); Y@MxKKuj
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); UM21Cfqex
fileSplitterFetch.start(); kqo4 v;r
} :2vuc!Pu
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j8^#698X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); t*Z5{
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", FBouXu#
nEndPos = " + nFileLength); !lsa5w{
// fileSplitterFetch[nPos.length-1].start(); |90/tNe
}>621L3 -
+N2ILE8[<
//等待子线程结束 g@/}SJh/>
//int count = 0; TEj"G7]1$A
//是否结束while循环 -*T0Cl.
boolean breakWhile = false; KZAF9
PX/^*
K~3Y8ca
while(!bStop) pg_H'0R
{ ^AOJ^@H^>
write_nPos(); B^R44j]3"
Utility.sleep(500); ,v=pp;
breakWhile = true; QpoC-4F
x6Gl|e[jv
Tl]yl$
for(int i=0;i<nStartPos.length;i++) w6Mv%ZO_
{ TMsCl6dB
if(!fileSplitterFetch.bDownOver) tBl(E
{ ^x^(Rk}|
breakWhile = false; l)jP!k
break; f$dIPt(
} #a tL2(wJ
} )_o^d>$da
if(breakWhile) 4N7|LxNNl_
break; akCCpnX_d
swJQwY
]EQ*!
//count++; o:4#AkS
//if(count>4) _E6N*ORV
// siteStop(); zq?xY`E
} 8$X3J[_j
10m|?
2 1+[9
System.err.println("文件下载结束！"); Q~' \oWz
} 2!b##`UjA7
catch(Exception e){e.printStackTrace ();} `Nz`5}8.?
} .XkVdaX
`P:[.hRu
H<?s[MH[
//获得文件长度 -2 8bJ,
public long getFileSize() "d}ey=$h4
{ Co=Bq{GY
int nFileLength = -1; (#z6w#CU(
try{ ^7;s4q
URL url = new URL(siteInfoBean.getSSiteURL()); $2}%3{<j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); EUV8H}d5
httpConnection.setRequestProperty("User-Agent","NetFox"); &=:3/;c
ZYt<O
&Ll&A@yU
int responseCode=httpConnection.getResponseCode(); G)Y,*.,
if(responseCode>=400) uAoZ&8D6
{ @^g~F&Ta
processErrorCode(responseCode); HRu;*3+%>F
return -2; //-2 represent access is error D$NpyF.87
} X2:23j<
WlGT&m&2
d 792#Dc
String sHeader; O;}K7rSc
[U"/A1p
JB.U&
for(int i=1;;i++) uq54+zC
{ ]0|A\bE\S
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7~k=t!gTY
//Utility.log(in.readLine()); t&EY$'c
sHeader=httpConnection.getHeaderFieldKey(i); Nqz6_!
if(sHeader!=null) 0bIgOLP
{ n:k4t
if(sHeader.equals("Content-Length")) +#<Z/
{ M1*bT@6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); H?xYS| n
break; QH,(iX6RY
} o?a3hD
} "QiLu=Rq
else [9NrPm3d
break; x#R6Ez7
} ?0+g.,9
} e:C4f
catch(IOException e){e.printStackTrace ();} nf1 `)tXG
catch(Exception e){e.printStackTrace ();} P$*Ngt
\ a(ce?C
B_b5&M@
Utility.log(nFileLength); [8[<4~{
Y#=MN~##t
T5.^ w
return nFileLength; >V]9<*c
} ,j.bdlI#
jcBZ#|B7;
n5IQKYrg
//保存下载信息（文件指针位置） VRD^>Gi
private void write_nPos() MHye!T6fO\
{ 2\gIjXX"
try{ b>k2@
output = new DataOutputStream(new FileOutputStream(tmpFile)); C4|OsC7J
output.writeInt(nStartPos.length); {B6ywTK\`
for(int i=0;i<nStartPos.length;i++) ~(GNY5
{ $b53~
// output.writeLong(nPos); r`h".=oD
output.writeLong(fileSplitterFetch.nStartPos); ~<s^HP2U{
output.writeLong(fileSplitterFetch.nEndPos); urCTP.F
} ~{vB2
output.close(); kY{$[+-jR
} LNHi}P~
catch(IOException e){e.printStackTrace ();} { w sT
catch(Exception e){e.printStackTrace ();} v'S5F@ln
} BNI)y@E^X
:g^ mg-8
TOS'|xQ
//读取保存的下载信息（文件指针位置） dh&>E
private void read_nPos() [+xsX*+
{ HiH<'m"\.
try{ PB8g4-?p6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )4c?BCgy
int nCount = input.readInt(); R:R<Xt N`5
nStartPos = new long[nCount]; CgYX^h?Y9
nEndPos = new long[nCount]; WW&Wh<4
for(int i=0;i<nStartPos.length;i++) lmD[Cn
{ n9`]}bnX
nStartPos = input.readLong(); G43r85LO
nEndPos = input.readLong(); {P_7AM
} Fkq^2o ]
input.close(); _nxH;Za
} +{I" e,Nk
catch(IOException e){e.printStackTrace ();} %%>nM'4<
catch(Exception e){e.printStackTrace ();} $AE5n>ZD$
} b(Tvc
(j??
M6Np!0G
private void processErrorCode(int nErrorCode) e"NP]_vh,
{ #Nco|v
System.err.println("Error Code : " + nErrorCode); C"_ Roir?
} h0g?=hJq
/S1/ZI
Qx8(w"k*
//停止文件下载 CS(2bj^6D
public void siteStop() p:W]
{ .jk A'i@
bStop = true; ;+6><O!G
for(int i=0;i<nStartPos.length;i++) &);P|v`8
fileSplitterFetch.splitterStop(); kV4Oq.E
3JBXGT0gJ
5r~jo7
} N~l*//Ep
} P*~ vWYH9
//负责部分文件的抓取 1;V_E2?V
**FileSplitterFetch.java ~!8j,Bqs+z
*/ ka8Y+Gs
package NetFox; b.@4yW
LyWY\K a
[wnp]'+!
import java.io.*; b:p0@|y
import java.net.*; 0`-b57lF&
DZnqCu"J
%DXBl:!Y`
public class FileSplitterFetch extends Thread { K%x]:|,>M
g,]m8%GHE
J@6j^U
String sURL; //File URL -C3[:g
long nStartPos; //File Snippet Start Position s*<T'0&w0S
long nEndPos; //File Snippet End Position )`R}@(r.
int nThreadID; //Thread's ID U&Vu%+B
boolean bDownOver = false; //Downing is over rVl 8?uy
boolean bStop = false; //Stop identical fi%i 2Wy
FileAccessI fileAccessI = null; //File Access interface (tg9"C
; teM^zyI
-D'XxOI
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Bdb}4X rL
{ JcmJq fR
this.sURL = sURL; Dm5 Uy^F}
this.nStartPos = nStart; wL="p) TO.
this.nEndPos = nEnd; t&J A1|q
nThreadID = id; seBmhe5qR
fileAccessI = new FileAccessI(sName,nStartPos);//定位 h@G~'\8t
} LSJ.pBl\X
tO:JB&vO2
'xxM0Kn`
public void run() 7H< IO`
{ *URT-+'
while(nStartPos < nEndPos && !bStop) tzIP4CR~F&
{ "V26\
$6pLsX
/]!2k9u\
try{ Bps%>P~.
URL url = new URL(sURL); a{hc{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BOG.[?yx
httpConnection.setRequestProperty("User-Agent","NetFox"); _avf%OS
String sProperty = "bytes="+nStartPos+"-"; |.0~'
httpConnection.setRequestProperty("RANGE",sProperty); _OuNX.yrG
Utility.log(sProperty); M.- {->
~h;
4dPTrBQ?
InputStream input = httpConnection.getInputStream(); d9;&Y?fp
//logResponseHead(httpConnection); &|#[.ti1
B#jnM~fJz
nv@z;#&
byte[] b = new byte[1024]; |`#fX(=
int nRead; E(|A"=\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #5)/B
{ v>B412l
nStartPos += fileAccessI.write(b,0,nRead); __.MS6"N
//if(nThreadID == 1) f?)7MR=
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <;PKec
} J*$%d1
/[FDiJH2
Zdqm|_R[
Utility.log("Thread " + nThreadID + " is over!"); |;wc8;
bDownOver = true; gI;"PkN
//nPos = fileAccessI.write (b,0,nRead); `7:uc@
} eQu(3sYb
catch(Exception e){e.printStackTrace ();} j0; ~2W#G*
} :1j8!R5
} Si?s69
-GPJ,S V>
CMW4Zqau*
//打印回应的头信息 P7XZ|Td4*
public void logResponseHead(HttpURLConnection con) v4"Ukv
{ EXr2d"
for(int i=1;;i++) Nb&j?./
{ 3U{ mC}F
String header=con.getHeaderFieldKey(i); [-_{3qq<e
if(header!=null) |di(hY|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $5JeN{B
Utility.log(header+" : "+con.getHeaderField(header)); ]wU/yc)e
else O?Bf (y
break; fOHbgnL>
} x'x5tg
} 2MRd
JVX)>2&$
<.n,:ir
public void splitterStop() Gc`PO
{ c#{lXS^
bStop = true; j*?8w(!
} /f1]U LmC:
\(i'iC
{S{%KkAV
} 72OqXa*
A[+)PkR
0>BxS9?w
/* ay7\Ae]
**FileAccess.java ;^xM" {G8
*//文件访问(定位，写) u>fMO9X}2
package NetFox; 6U*CR=4
import java.io.*; bQautRW
MRt"#CO
W:RjWn@<
public class FileAccessI implements Serializable{ )hrsA&1w
D;0>-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rH`\UZ{cc
RandomAccessFile oSavedFile; i|1*bZ6'
long nPos; }( F:U#
toPbFU'
}9"''Z
public FileAccessI() throws IOException u @Ze@N%
{ w UxFE=ia
this("",0); e&z@yy$
} )\Q(=:
xA Ez1
ck{S
public FileAccessI(String sName,long nPos) throws IOException ,<%uG6/",g
{ xkDK5&V
oSavedFile = new RandomAccessFile(sName,"rw"); "KP]3EyPc
this.nPos = nPos; 6NX#=A
oSavedFile.seek(nPos); F9o7=5WAb
} \lQ3j8U
-fPiHKJ
_l7_!Il_
public synchronized int write(byte[] b,int nStart,int nLen) O"'xAPQW
{ }e$
int n = -1; ,N(Yjq"R
try{ P'qBqx[
oSavedFile.write(b,nStart,nLen); jvB[bS`<H
n = nLen; V gMgeja
} YYn8!FIe
catch(IOException e) BFW b0;+
{ yIKpyyC9H
e.printStackTrace (); _!o8s%9be
} $!*>5".A
/3aW 0/^o
o9e8Oj&
return n; T9V=#+8#"
} Bn]=T
E_=F'sP?
jXeE]A"
} T>asH
.1[.f}g$J
CImp,k0
/* G"?7 Z&+
**SiteInfoBean.java Xeq9Vs zg
*/ <Ja&z M
package NetFox; F NPu
SQ,-45@W
wL8ji>"
public class SiteInfoBean { X\Bl? F
\B4H0f
aPelt`
private String sSiteURL; //Site's URL gw"cXny
private String sFilePath; //Saved File's Path Cy?]o?_?
private String sFileName; //Saved File's Name 1]:,Xa+|S
private int nSplitter; //Count of Splited Downloading File {KHI(*r;
M3-lL;!n
,A{Bx`o?
public SiteInfoBean() DKt98;
{//nSplitter的缺省值为5 C<J*C0vQO
//default value of nSplitter is 5 8S#$'2sT
this("","","",5); X "7CN Td
} B`-uZ9k
k3$'K}=d
VF2,(f-*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) qIuo8o}
{ .5Y{Yme
sSiteURL= sURL; U6/7EOW,
sFilePath = sPath; W$`v^1M2o
sFileName = sName; ( 3B1X
this.nSplitter = nSpiltter; o)5zvnu7
J-<P~9m~I
vE)N6Ss
} gg#9I(pX
hhPQ.{]>
g*b`o87PI
public String getSSiteURL() c)#7T<>*'
{ R7Qj<,
return sSiteURL; ywp_,j9F
} aaU4Jl?L
PFp!T [)
01@WU1IN
public void setSSiteURL(String value) "^z%|uXkf
{ [l^XqD D4
sSiteURL = value; ,mm97I
} 'df@4}9
'|]}f}Go
Mk#r_:[BS
public String getSFilePath() tkV[^OeU>
{ a&G{3#l
return sFilePath; aiX&`
} c<_1o!68
Jy:*GW6
nq?+b >//
public void setSFilePath(String value) ;cf$u}+
{ -I{op wd
sFilePath = value; /ZiMD;4@y
} B)7:*Kj
di_UJ~
10zM8<bl
public String getSFileName() $DH/
{ TkTGYh
return sFileName; KLM6#6`
} ;sA 5&a>!
mH;t)dT
8-+# !]
public void setSFileName(String value) by9UwM=gp
{ 0>j0L8#^p
sFileName = value; ds(X[7XGW
} / P@P1l|I
Uot(3p!S6
\68bXY.
public int getNSplitter() _lI(!tj(
{ 8Q/cJ+&
return nSplitter; Tg O]q4
} H8"RdKwg?
g&/lyQ+G
"n3n-Y#'
public void setNSplitter(int nCount) RQ|K?^k v
{ Vfd_nD^8oZ
nSplitter = nCount; ISZEP8w
} ^Vth;!o
} t@lTA>;U@
" AvEo
i8Be%y%y
/* A*qR<cp[
**Utility.java `vt+VUNf
*/ YH^U"\}i
package NetFox; (~\HizSl
fATnza
y46sL~HRv
public class Utility { U{EcV%C2
Dp*:oMATx0
uUaDesz~=
public Utility() ?a+J4Zr3
{ D {E,XOi
tWZ8(E$
CiU^U|~'L
} Q.4+"JoG
}}Q h_(
//线程睡眠 _JpTHpqu
public static void sleep(int nSecond) wD
{ [Ketg
try{ C.=%8|Zy
Thread.sleep(nSecond); F$v^S+Ch
} cPL6(&7
catch(Exception e) l}S96B
{ sFk{Tv@Yz
e.printStackTrace (); 'u PI~l`g
} JvT#Fxjk
} 4nd)*0{f
Ktuv a3=>N
//日志 Xhyc2DKa_
public static void log(String sMsg) %MtaWZ
{ (Gzq 1+B
System.err.println(sMsg); :gkn`z
} *Q-uE
'&AeOn
>r:z`^p
public static void log(int sMsg) 4[r:DM|8
{ bA"*^"^
System.err.println(sMsg); 7'.6/U
} #)DDQ?D
} A9HgABhax
(ia+N/$u
?6[u\V
/* e oFM
**TestMethod.java 7m(9|Y:Q.
*/ l>Zp#+I-
package NetFox; @MH/efW.
Hg]iZ,8?
(=53WbOh/t
public class TestMethod { ~:="o/wo
L@ N\8mf
&C/,~pJ1S
public TestMethod() QUdF`_U7
{ ///xx/weblogic60b2_win.exe DQ6pe)E|
try{ AdF[>Wv
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); I} ]s(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); oM}P Wf-
SiteFileFetch fileFetch = new SiteFileFetch(bean); / vzwokH
fileFetch.start(); rYyEs I#qo
} g3w-Le&T
catch(Exception e){e.printStackTrace ();} s\ ]Rgi>w
_l]rt
W<H^V"^
} ra\2BS)X
1z8AK"8
0j-;4>p
public static void main(String[] args) mhnK{M @56
{ ;Uj=rS`Q
new TestMethod(); KMkX0+Ao
} {uO2m*JrI
} %lK]m`(
点击下载更多相关资料