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)); oH0F9*+W
} d/rz0L
for(int i=0;i<nEndPos.length-1;i++) 6JYOe
{ D ;$+]2
nEndPos = nStartPos[i+1]; O/oYaAlFF@
} '<S:|$$
nEndPos[nEndPos.length-1] = nFileLength; v=1S
} iGVb.=)
} ^l&4UnLlc
VQMd[/
]},Q`n>$
//启动子线程 [Vp2!"
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <L/vNP
for(int i=0;i<nStartPos.length;i++) p+UHJ&
{ M`pTT5r
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .+L_!A
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4Olv8nOe<
nStartPos,nEndPos,i); . ]o3A8
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ioC@n8_[G
fileSplitterFetch.start(); ~Na=+}.q_
} a -xW8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "t[M'[ `C
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); On{~St'V
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", lQV|U;~D
nEndPos = " + nFileLength); _ yfdj[Ot`
// fileSplitterFetch[nPos.length-1].start(); X5uS>V%/
] vC=.&]
|Z`M*.d+
//等待子线程结束 V I6\
//int count = 0; a'@-"qk
//是否结束while循环 $uEJn&n7}
boolean breakWhile = false; Xw7{R
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while(!bStop) 7"ylN"syZ
{ uy/y wm/?=
write_nPos(); AIuMX4nb
Utility.sleep(500); -"W)|oC_
breakWhile = true; :8p&#M
BRQ"A,
R<f#r03@|
for(int i=0;i<nStartPos.length;i++) (wife#)~
{ I-,>DLG
if(!fileSplitterFetch.bDownOver) A^-iHm
{ `aIG;@Z
breakWhile = false; /J;;|X#P
break; {B3(HiC
} H"_v+N5=
} KGu= ;
if(breakWhile) Vc|NL^
break; *%X.ym'
T8U[xu.>
=^Th[B
//count++; q-YL]PgV
//if(count>4) x@Y|v@}BE
// siteStop(); Rb#/qkk/
} pw=F' Y@N
hcyn
}wfI4?}j}
System.err.println("文件下载结束！"); ^p,3)$
} 2 l(Dee Y
catch(Exception e){e.printStackTrace ();} Xtkw Z3
} 8)pB_en3sO
L?HF'5o
~ 7}]
//获得文件长度 ilv_D~|
public long getFileSize() >Fyu@u
{ zrrz<dW
int nFileLength = -1; :9`qogF>
try{ 4`s)ue
URL url = new URL(siteInfoBean.getSSiteURL()); `y2ljIWJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -bA!PeI
httpConnection.setRequestProperty("User-Agent","NetFox"); M"(6&M=?
Dx3%KS
JNBT^=x
int responseCode=httpConnection.getResponseCode(); R hio7C
if(responseCode>=400) ~^7r?<aKc
{ JYV\oV{
processErrorCode(responseCode); wAh#
return -2; //-2 represent access is error zQc"bcif5(
} k 4B_W
OQFi.8
a5?A!k\2
String sHeader; B{aU;{1
W-XpJ\_
ffk4mhH
for(int i=1;;i++) wyw<jH
{ tS<h8g_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); XWtiwf'K
//Utility.log(in.readLine()); nU17L6'$
sHeader=httpConnection.getHeaderFieldKey(i); PN &|8_
if(sHeader!=null) azX`oU,l
{ )%VCzye*{
if(sHeader.equals("Content-Length")) GV8)Kor%
{ kA^A mfba
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); a,n93-m(m
break; gz61FW
} 5B*qbM
} $.:3$et@/
else sPCMckt
break; y5u\j{?Te
} )gXTRkmw
} _~A~+S}
catch(IOException e){e.printStackTrace ();} DYRE1!
catch(Exception e){e.printStackTrace ();} %F J#uQXZ
~`R1sSr"
G{o+R]Us
Utility.log(nFileLength); z+/LS5$
}OrYpZob
/DO'IHC.o
return nFileLength; UX_I6_&
} zfjw;sUX
?"j@;/=
9":2"<'+
//保存下载信息（文件指针位置） LgHJo-+>
private void write_nPos() .pvxh|V
{ <xlm K(
try{ Mm#[&j[Y
output = new DataOutputStream(new FileOutputStream(tmpFile)); gs`> C(
output.writeInt(nStartPos.length); [5Y<7DS
for(int i=0;i<nStartPos.length;i++) <&U!N'CE
{ (WE,dY+.
// output.writeLong(nPos); }-p,iTm
output.writeLong(fileSplitterFetch.nStartPos); zu<3^=3
output.writeLong(fileSplitterFetch.nEndPos); @^?XaU
} YwAnqAg
output.close(); kon=il<@
} Ei~f`{i
catch(IOException e){e.printStackTrace ();} QlD6i-a
catch(Exception e){e.printStackTrace ();} ~lw<799F6
} U9#WN.noG
5AOfp2O
#C\4/g?=,
//读取保存的下载信息（文件指针位置） Jqru AW<
private void read_nPos() >Z\BfH
{ ]a/'6GbR
try{ GZ8:e3ri
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xo WT*f
int nCount = input.readInt(); a+?~;.i~
nStartPos = new long[nCount]; 'm O2t~n
nEndPos = new long[nCount]; Oh`2tc-
for(int i=0;i<nStartPos.length;i++) (X}@^]lpa
{ T~s}Nx#
nStartPos = input.readLong(); yVS\Q,:J9
nEndPos = input.readLong(); sKfXg`0
} wFL3&*
input.close(); 84M3c
} 70Ka!
catch(IOException e){e.printStackTrace ();} 3ATjsOL
catch(Exception e){e.printStackTrace ();} `|<+ ?
} (~()RkT
Vk7=7%xW
<4mQ*6
private void processErrorCode(int nErrorCode) g:gB`8w?
{ ^\wl2
System.err.println("Error Code : " + nErrorCode); inF6M8 A1
} n}J^6:1
SxMj,u%X/
o6|-=FcvC
//停止文件下载 0H:dv:#WAI
public void siteStop() HXks_ix )
{ R]QpMj%o
bStop = true; C5n?0I9
for(int i=0;i<nStartPos.length;i++) 5I,$EGG
fileSplitterFetch.splitterStop(); Ze ? g
s[c^"@HT
eb!_ie"D
} ^l!L)iw
} CV^c",b_
//负责部分文件的抓取 `="v>qN2\
**FileSplitterFetch.java 7GZq|M_:y
*/ Z2p> n`D
package NetFox; +t]Xj1Q
yP\Up
("Dv>&w9
import java.io.*; ZBc|438[
import java.net.*; 8D~x\!(p\
rt b*n~
k dU! kj
public class FileSplitterFetch extends Thread { @]'SeiNp
g%\L&}Jd
qm(1:iK,0
String sURL; //File URL 1^{`lK~2
long nStartPos; //File Snippet Start Position \*"`L3
long nEndPos; //File Snippet End Position km\%BD~
int nThreadID; //Thread's ID nNn56&N]
boolean bDownOver = false; //Downing is over fk3kbdI
boolean bStop = false; //Stop identical 8/Rm!.8+~
FileAccessI fileAccessI = null; //File Access interface c8DZJSO
`ROEV~
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $a.u05
{ n33kb/q*
this.sURL = sURL; U9ZbVjqv@
this.nStartPos = nStart; a8s4T$
this.nEndPos = nEnd; b!a %YLL
nThreadID = id; >oqZ !V5[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |9,UaA
} Z> 74.r
p`>d7S>"
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public void run() I/s.xk_i
{ J22rv(
while(nStartPos < nEndPos && !bStop) '29WscU
{ ;$!I&<)
aWaw&u
Rd! 2\|
try{ b5 Q NEi
URL url = new URL(sURL); Tsz NlRxc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jA`a/vWu
httpConnection.setRequestProperty("User-Agent","NetFox"); W_<4WG
String sProperty = "bytes="+nStartPos+"-"; iBvOJs
httpConnection.setRequestProperty("RANGE",sProperty); ty- r&
Utility.log(sProperty); y/R+$h(%
j Z'&0x"U
- L~Uu^o
InputStream input = httpConnection.getInputStream(); 0HbJKix!
//logResponseHead(httpConnection); <abKiXA"
-p8e
"!q?P" @C
byte[] b = new byte[1024]; bK=c@GXS
int nRead; PDC]wZd/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -g~~]K%
{ %f!iHo+Z
nStartPos += fileAccessI.write(b,0,nRead); 7~vqf3ON4J
//if(nThreadID == 1) XO wiHW{
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V0NVGRQ
} 1xTTJyoq
YIOR$
gX*K&*q
Utility.log("Thread " + nThreadID + " is over!"); gaeOgP.0
bDownOver = true; J}@GKNm
//nPos = fileAccessI.write (b,0,nRead); %h+uD^^$
} +X^4; &
catch(Exception e){e.printStackTrace ();} MY F#A
} LK+felL
} _A-V@%3
6%?A>
{tt$w>X
//打印回应的头信息 ~ hm`uP
public void logResponseHead(HttpURLConnection con) `P.CNYR<J
{ &r@H(}$1\
for(int i=1;;i++) ,F:=(21
{ (~#G'Hd
String header=con.getHeaderFieldKey(i); }1m_o@{3P
if(header!=null) "{( [!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ( V4G<-jG
Utility.log(header+" : "+con.getHeaderField(header)); O5-;I,)H
else x!?Z*v@I
break; M 9"-WIG@h
} 2Xgx*'t\
} D[~}uZ4\
q^Inb)FeN
]{Ek[Av
public void splitterStop() xIgql}.
{ =|0/Ynfe
bStop = true; l0`'5>
} dS$ji#+d$
fn1pa@P
G(\Ckf:
} RgGA$HN/
p >aw
'v`_Ii|-
/* Yy@g9mi
**FileAccess.java `Zf9$K|
*//文件访问(定位，写) BKA]G)G7u!
package NetFox; XGIpUz
import java.io.*; wLMvC{5
bi,mM,N/
an KuTI
public class FileAccessI implements Serializable{ q6&67u0
-eL'KO5'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /f&By p
RandomAccessFile oSavedFile; b *9-}g:
long nPos; `a'`$'j
a#QByP
)ddsyFGW
public FileAccessI() throws IOException P6we(I`"2
{ +*a7GttU
this("",0); IJIQ" s
} S'@=3)
ND*]gM
BD'NuI
public FileAccessI(String sName,long nPos) throws IOException xt))]aH
{ kY!C_kFcn
oSavedFile = new RandomAccessFile(sName,"rw"); i4VK{G~g"
this.nPos = nPos; $e1:Q#den2
oSavedFile.seek(nPos); V6+Zh>'S
} %MuaW(I o
3{pk5_c
x@Vt[}e
public synchronized int write(byte[] b,int nStart,int nLen) (UcFNeo
{ tgW kX
int n = -1; /e<5Np\X
try{ fq(5Lfe}
oSavedFile.write(b,nStart,nLen); (H-cDsh;c
n = nLen; 9K$]h2
} 8^T2^gs
catch(IOException e) UoRDeYQ`E
{ 8t\}c6/3"
e.printStackTrace (); Ky6+~>
} 6eo4#/+%
H:Lt$
r=0j7^B#
return n; ,D8&q?a
} GLcd9|H
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e>!E=J)j
} kjX7- ZPY
b[0S=e G
zn^v!:[
/* 9A<0zt
**SiteInfoBean.java xFX&9^Uk
*/ ['t8C
package NetFox; 6KB^w0oA
[Q:f-<nH
to51hjV
public class SiteInfoBean { 3W'FcE)|E
o}W;Co
',#
private String sSiteURL; //Site's URL e&ts\0
private String sFilePath; //Saved File's Path yDuq6`R*
private String sFileName; //Saved File's Name CPGL!:
private int nSplitter; //Count of Splited Downloading File z \^
Se/ss!If
N-Z^G<[q.
public SiteInfoBean() `fMpV8vv
{//nSplitter的缺省值为5 _G[6+g5|
//default value of nSplitter is 5 `~h0?g
this("","","",5); ;L$,gn5H
} d.I%k1`(
g41<8^(
#@q1Ko!NZ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1~L\s}|2d
{ 5f{wJb2
sSiteURL= sURL; [x|)}P7%s
sFilePath = sPath; ~.H~XKw
sFileName = sName; *F..ZS'$[
this.nSplitter = nSpiltter; 7P c(<Ui+
gtMw3D`FL
4`6< {
} ExqM1&zpK
dXDXRY.FMQ
6qf-Y!D5
public String getSSiteURL() =tHD 4I
{ yH+c#w
return sSiteURL; }EP|Mb
} I<KCt2:X
ovSH}h!
"G@E6{/
public void setSSiteURL(String value) 'rvE
{ w#rVSSXQ3
sSiteURL = value; :U8k|,~f
} }Wqtip:L
D>S8$]^Dm
w?i)/q
public String getSFilePath() :S#i9# aB
{ }q]jjs
return sFilePath; K,]woNxaw
} r\B"?oqC
.}`V I`z*
h*l cEzG?A
public void setSFilePath(String value) VH[l\I(h
{ ys/vI/e\
sFilePath = value; =CEHRny
} JC/d:.
!L/tLHk+
}]`}Ja
public String getSFileName() >gF-6nPQ
{ c|+y9(0|y
return sFileName; *s~i 2}
} kM,@[V
0+rW;-_(
j+ I*Xw
public void setSFileName(String value) =^#0.
{ g(1"GKg3K
sFileName = value; $.;iu2iyo
} ]M uF9={
K1<k+t/V
JLml#Pu4
public int getNSplitter() g4i #1V=
{ b13nE.
return nSplitter; DVbYShB
} ^^7gDgT
n00z8B1j(l
UYH|?Jw!N
public void setNSplitter(int nCount) 4I z.fAw
{ f^~2^p 1te
nSplitter = nCount; 3|jn,?K)N
} s *K:IgJ/
} MV9r5|3-
NWeV>;lh9
5%'o%`?i
/* Nz}|%.GP"
**Utility.java $vz_%Y
*/ { qjUI
package NetFox; r.?qEe8VV
GsI[N%
. c#90RP
public class Utility { Oxpo6G
58 kv#;j
2lF WW(
public Utility() y)0gJP L^
{ <. ezw4ju
r!CA2iK`
$tEdBnf^ca
} HhzkMJR8
r}Ltv?4
//线程睡眠 nMLU-C!t
public static void sleep(int nSecond) Sb^add0dT
{ {npOlV
try{ hZ%2?v`
Thread.sleep(nSecond); ]Qh[%GD
} :{x!g6bK@
catch(Exception e) kBQ5]Q"
{ C+DG+_%V*S
e.printStackTrace (); _xa}B,H
} 2-QuT"Gkd
} {_rZRyr
'W}~)+zK
//日志 g9M')8a n
public static void log(String sMsg) b$PT_!d
{ NJ.rv
System.err.println(sMsg); ,"x23=]
} Pv^(Q]
<yis
4 `j,&=
public static void log(int sMsg) 6\%r6_.d
{ B>ms`|q=l
System.err.println(sMsg); f34_?F<h
} 6s> sj7
} ~W2:NQ>i
9yO{JgKA
qn5yD!1
/* @?'t@P:4
**TestMethod.java ~JAH-R
*/ #8P#^v]H
package NetFox; 1'(_>S5CG
`i"$*4#<
Z|V"8jE
public class TestMethod { <\B],M1=s=
NEjPU#@c
Xw&QrTDS`
public TestMethod() :!r9 =N9
{ ///xx/weblogic60b2_win.exe le "JW/BD
try{ 1EKcD^U,
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !l sy&6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Oz"@yL}
SiteFileFetch fileFetch = new SiteFileFetch(bean); e-L5=B
fileFetch.start(); 67Af} >Q
} )->-~E}p9
catch(Exception e){e.printStackTrace ();} 2U-#0,ll]
ls8olLM>
e[d7UV[Knn
} Zkwy.Hq^
2+c>O%L
M Ak-=?t
public static void main(String[] args) }CB=c]p
{ MAm1w'ol"
new TestMethod(); oO!1
} (mD-FR@#
} /\IAr,w[
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