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)); f!0*^d
} 6'+3""\
for(int i=0;i<nEndPos.length-1;i++) Y2QlK1.8V
{ l#V"14y
nEndPos = nStartPos[i+1]; O .m;a_
} |f?tyQ
nEndPos[nEndPos.length-1] = nFileLength; 9m%[ y1v0
} b2r@vZ]D
} [bH6>{3u
K7U`
Fl<BCJY
//启动子线程 ()=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; iK= {pd
for(int i=0;i<nStartPos.length;i++) I[@}+p0
{ N[z7<$$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), / ~w\Npf0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5e6]v2 k
nStartPos,nEndPos,i); G8Ns?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y]+i.8[
fileSplitterFetch.start(); \C~Y
} 50uNgLs
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /i"L@t)\t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); YeptYW@xfw
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _;L9&>!p6
nEndPos = " + nFileLength); ^MKvZ DOP
// fileSplitterFetch[nPos.length-1].start(); 9ZeTS~i
D CcM~
'8}*erAg
//等待子线程结束 ja#E}`wC4
//int count = 0; ]fnc.^{
//是否结束while循环 o!gl :izb
boolean breakWhile = false; =K-B I
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while(!bStop) Qt+ K,LY
{ -|"mB"Dc
write_nPos(); w8%<O^wN,
Utility.sleep(500); 1|q$Wn:*
breakWhile = true; )$]_;JFr
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gH(,>}{^K
for(int i=0;i<nStartPos.length;i++) K8ecSs}}J
{ b'3w.%^
if(!fileSplitterFetch.bDownOver) (/-2bO
{ /{."*jK
breakWhile = false; 9~SfZ,(
break; A<ur20
} wFnIM2a,
} B|/=E470G
if(breakWhile) cX9 !a,
break; 4 B"tz!
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&S>m+m'
//count++; V<ziJ7H/
//if(count>4) am]$`7R5d
// siteStop(); W}50E.\#
} Ze~^+ EE
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_%?}e|epy
System.err.println("文件下载结束！"); '+hiCX-_
} qfd/t<?|D
catch(Exception e){e.printStackTrace ();} Cb%?s
} Q"h/o"-h
2,{m>fF
ypSW9n
//获得文件长度 Mm;kB/1
public long getFileSize() Jlj=FA`
{ %oJ_,m_(
int nFileLength = -1; CE=&ZHt9
try{ l&R~I6^E
URL url = new URL(siteInfoBean.getSSiteURL()); EC<g7_0F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3P2H!r
httpConnection.setRequestProperty("User-Agent","NetFox"); Gc^w,n[E
Fo|6 PoSo
jeFX?]Q
int responseCode=httpConnection.getResponseCode(); ^i&sQQ({
if(responseCode>=400) a^hDxeG
{ xX.fN7[
processErrorCode(responseCode); k1e0kxn
return -2; //-2 represent access is error "94e-Nx
} kAsYh4[
f"\G"2C
q"7rd?r52
String sHeader; D(yU:^L
U p=J&^.
O8%+5l`T!
for(int i=1;;i++) =;#+8w=^
{ u0(H!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Ikv@}^p 7
//Utility.log(in.readLine()); $p#)xx7
sHeader=httpConnection.getHeaderFieldKey(i); \dO9nwa?
if(sHeader!=null) W3Oj6R
{ u,mC`gz
if(sHeader.equals("Content-Length")) 4D=p#KZ
{ gXBC= ?jl
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Q x}\[
break; [xe(FFl+
} g <S&sYF5
} L #c*)
else Q(=} PF
break; h;?=:(
} `dO)}}| y
} Xxhzzm-B
catch(IOException e){e.printStackTrace ();} 00X~/'!
catch(Exception e){e.printStackTrace ();} \bNN]=
e"Kg/*Ji1
Y3KKskhLx
Utility.log(nFileLength); .aTu]i3l_
E&ou(Q={
XUTI0
return nFileLength; DC4O@"
} _+73Y'
b9b384Q1O
gmtp/?>e
//保存下载信息（文件指针位置） Jn!-Wa,
private void write_nPos() hfw$820y[
{ \Jq$!foYx
try{ ^x8*]Sz#x
output = new DataOutputStream(new FileOutputStream(tmpFile)); }q7rR:g
output.writeInt(nStartPos.length); ;;#28nV
for(int i=0;i<nStartPos.length;i++) //T1e7)
{ `}<x"f7.z
// output.writeLong(nPos); GvQKFgO6h
output.writeLong(fileSplitterFetch.nStartPos); /Z`("X?_Kf
output.writeLong(fileSplitterFetch.nEndPos); E_k<EQ%r
} LE#ko2#ke
output.close(); mhU ?N
} U\dq Mp#Wy
catch(IOException e){e.printStackTrace ();} {8`V5:
catch(Exception e){e.printStackTrace ();} 6vy(@z
} =pSuyM'
Zt;3HY=y
I.#V/{J
//读取保存的下载信息（文件指针位置） AT*J '37
private void read_nPos() 7L2$(d4
{ |&!04~s;E
try{ 0*G =~:
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *q**,_?;
int nCount = input.readInt(); |e49F
nStartPos = new long[nCount]; u By[x 0
nEndPos = new long[nCount]; =qG%h5]n
for(int i=0;i<nStartPos.length;i++) cXP*?N4Cf
{ t6m&+N
nStartPos = input.readLong(); `P/7Mf
nEndPos = input.readLong(); |Rk9W
} Z{&dzc
input.close(); vw(X9xa
} tgeX~.
catch(IOException e){e.printStackTrace ();} #( G>J4E,
catch(Exception e){e.printStackTrace ();} aLa{zB
} +$_.${uwV
}e[;~g\&
n~`1KC4
private void processErrorCode(int nErrorCode) zb<YYJ]
{ OAx5 LTd
System.err.println("Error Code : " + nErrorCode); ;QZ}$8D6Q
} E&js`24 &
@q8h'@sX
4R<bfZ43
//停止文件下载 y8~/EyY|^
public void siteStop() (|Zah1k&]
{ e0rh~@E
bStop = true; Qy< ~{6V
for(int i=0;i<nStartPos.length;i++) ICq
fileSplitterFetch.splitterStop(); 9*`(*>S
/XEt2,sI9
qRk<1.
} Zw4z`x1f
} /O@TqH
//负责部分文件的抓取 R1A|g=kF
**FileSplitterFetch.java z''ITX)oG
*/ $"#2hVO
package NetFox; 8nKZ
z _A]mJ
04npY+1 8%
import java.io.*; -l)u`f^n|
import java.net.*; Q:rQ;/b0/
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b# v+_7
public class FileSplitterFetch extends Thread { .lbo\v}2W
LHJ}I5zv
)H HBf<
String sURL; //File URL 8Qm%T7]UFb
long nStartPos; //File Snippet Start Position k+nfW]UNF
long nEndPos; //File Snippet End Position ~6bf-Wg'X
int nThreadID; //Thread's ID ! J7ExfEA
boolean bDownOver = false; //Downing is over 5}v<?<l9\
boolean bStop = false; //Stop identical RH^!7W*
FileAccessI fileAccessI = null; //File Access interface u(kacQ7
',>Pz+XKc
jPum2U_
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException J]m[0g7O_
{ @cc4]>4
this.sURL = sURL; G&7!3u
this.nStartPos = nStart; Dej_(Dz_S
this.nEndPos = nEnd; 0<^!<i(%
nThreadID = id; d<,'9/a>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 = ^NTHc^*
} 16pk4f8
L'A>IBrz
1\XR6q:2
public void run() >5%;NI5 G
{ >)+-:
while(nStartPos < nEndPos && !bStop) 3_5]0:?]-
{ ZjB]pG+
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try{ N?Nu'
URL url = new URL(sURL); }I )%Gw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |O!G[|/3
httpConnection.setRequestProperty("User-Agent","NetFox"); kuX{2h*`
String sProperty = "bytes="+nStartPos+"-"; q2SlK8`QJ
httpConnection.setRequestProperty("RANGE",sProperty); 7k<6oM1
Utility.log(sProperty); BSyl!>G6n8
45 \W%8
igGg[I1?
InputStream input = httpConnection.getInputStream(); %k+G-oT5
//logResponseHead(httpConnection); &N+i3l6`
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He1hgJ)N
byte[] b = new byte[1024]; tjId?}\
int nRead; jeu|9{iTVu
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8c%Sd'+Pt
{ LtK= nK
nStartPos += fileAccessI.write(b,0,nRead); m ?)k&{I
//if(nThreadID == 1) @,\J\ rb
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l(~i>iQ 4
} ^J]_O_ee$
/%F}vW(!
p)k5Uh"
Utility.log("Thread " + nThreadID + " is over!"); 9-`P\/
bDownOver = true; e'y$X;nIv
//nPos = fileAccessI.write (b,0,nRead); hKjG/g:#G
} q4xP<b^
catch(Exception e){e.printStackTrace ();} y' r I1eF
} [t}@>@W|
} Quts~Q
pRez${f.(s
m|by^40A(
//打印回应的头信息 pl4:>4l/
public void logResponseHead(HttpURLConnection con) Tu[I84
{ C" 2K U*
for(int i=1;;i++) g^mnYg5
{ SJai<>k h
String header=con.getHeaderFieldKey(i); ~!iZn
if(header!=null) Acl?w }Y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r:~q{
Utility.log(header+" : "+con.getHeaderField(header)); +U^H`\EUr
else V/dL-;W;
break; ^VOA69n>$
} -TT{4\%s
} 1Z_2s2`p
&W*do
%p}xW V.
public void splitterStop() |!?lwBs4
{ /hv2=A
bStop = true; .[Nr2w:>
} k>V~iA
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0Z&ua
} j0.E!8Ae{
G^W'mV$xl
t4H*&U
/* x1'4njTV$
**FileAccess.java C9VtRq
*//文件访问(定位，写) AcQmY?
package NetFox; IW$qP&a
import java.io.*; XlaGR2-%
i[O{M`Z%
}9*NEU)o
public class FileAccessI implements Serializable{ (/^dyG|X'
3;<Vv*a"Dm
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 I*`;1+`
RandomAccessFile oSavedFile; %c-T Gr,
long nPos; `#c36
JF6=0
.:(T}\]R
public FileAccessI() throws IOException r=4vN=:
{ *!c&[- g
this("",0); ,w|Or}h]7
} x4Wu`-4^
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zk^uS#
public FileAccessI(String sName,long nPos) throws IOException =}OcMM`f
{ 3T)_(SM"
oSavedFile = new RandomAccessFile(sName,"rw"); 5STk"
this.nPos = nPos; {9;x\($&a
oSavedFile.seek(nPos); 3'xmq
} [;LP6n7v
}c@duf-l
dUc([&
public synchronized int write(byte[] b,int nStart,int nLen) @@=e-d
{ 557%^)v
int n = -1; :7L[v9'
try{ ltg\x8w?c
oSavedFile.write(b,nStart,nLen); z>A;|iL
n = nLen; WCL#3uYk"
} M}\p/r=
catch(IOException e) K]H [A,
{ m;oCi}fL
e.printStackTrace (); |rL#HG
} O3En+m~3n)
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qL2Sv(A Z!
return n; D^<5gRK?
} I/k/5
X ApSKJ
D&|HS!
} v:zKn[;o
mBON>Z[4.
^"GDaMF
/* Rxl/)H[Lc"
**SiteInfoBean.java 6vr8rJ-
*/ nPg,(8Tt
package NetFox; YtFH@M
()ZP=\L
T_I ApC
public class SiteInfoBean { rvG0aqO`
/?B%,$~
|gwGCa+
private String sSiteURL; //Site's URL >)8<d3m
private String sFilePath; //Saved File's Path = 6.i.(L_S
private String sFileName; //Saved File's Name WJBwo%J
private int nSplitter; //Count of Splited Downloading File dCO7"/IHW
>7(7
.-?Txkwb
public SiteInfoBean() x#jJ 0T
{//nSplitter的缺省值为5 yGE)EBH
//default value of nSplitter is 5 :S=!]la0h
this("","","",5); %~EOq\&
} ~n{lu'SIX2
6e4A|<
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !~!\=etm
{ U*cWNn:."
sSiteURL= sURL; kPezR: 31
sFilePath = sPath; _qU;`Q
sFileName = sName; ~ea&1+Z[3
this.nSplitter = nSpiltter; oA`G\Xh_E
-5u. Ix3
PD`EtkUnv
} 'da$i
Ch7&9NW
ds:&{~7L<T
public String getSSiteURL() .s`7n *xz
{ 5O]eD84B
return sSiteURL; sHm:G_
} CW'<Nh
4R28S]Gb
B/gI~e0
public void setSSiteURL(String value) JTdcLmL
{ a8cX{6
sSiteURL = value; C sx EN4
} Z/+H
22gh,e2o
6bd{3@
public String getSFilePath() N7#,x9+E
{ yq,%<%+
return sFilePath; .v[!_bk8C
} (Z#j^}G_l
{9|S,<9
Q'c[yu
public void setSFilePath(String value) /[=U$=uH
{ m?]= =9
sFilePath = value; drd5oZ
} uYMH5Om+i
=aCd,4B}
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public String getSFileName() Tk:%YS;=
{ ~NBlJULS
return sFileName; #waK^B)<a
} u=&$Z
yPT\9"/
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public void setSFileName(String value) =e|
{ %40+si3c
sFileName = value; 9}#9i^%}
} "fWm{;
0s%]%2ON
&U{"dJr
public int getNSplitter() 'aJm4W&j
{ /9(8ML#E
return nSplitter; laA3v3*
} B5MEE
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public void setNSplitter(int nCount) zD): yEc
{ \5R>+[n!
nSplitter = nCount; ^/"2s}+
} 3TF'[(K=
} W0s3nio
p^U#1c
aT}?-CUxx
/* P/ 7aj:h~P
**Utility.java L^{wxOf&6E
*/ {!37w[s~
package NetFox; % QI6`@Y"
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*>J45U(6:
public class Utility { g<5G#
%nT&
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public Utility() 28=L9q
{ >|_B=<!99W
4 ky/a1y-
Fu"@)xw/-q
} ;1L7+.A
AS]jJc^
//线程睡眠 !?J?R-C
public static void sleep(int nSecond) 5gbD|^ij
{ 0=c:O
try{ 2hFj+Ay
Thread.sleep(nSecond); /V f L(
} ;BjJ<?^{
catch(Exception e) [eZ'h8
{ q\T}jF\t
e.printStackTrace (); , \R,O
} .q_SA-!w>
} HFTDea+#
TDY =!
//日志 '^~38=FA
public static void log(String sMsg) mBWhC<kKs
{ <7yn:
System.err.println(sMsg); sZYTpZgW4L
} vC_O!2E
i=j4Wg,{J
.p /VRlLU
public static void log(int sMsg) +e( (!
{ } f+hB
System.err.println(sMsg); ,7*-%05[\
} ~R\U1XXyUY
} vp..>BMJ
Wkc^?0p
VO+3@d:
/* ["XS|"DM
**TestMethod.java C^!ej"
*/ E K#ib
package NetFox; eVB.g@%T
p="K4E8~H
{uji7TB
public class TestMethod { MD=VR(P?eq
v m)'CC
HK!Vd_&9,
public TestMethod() Y~uqKb;A
{ ///xx/weblogic60b2_win.exe v9+1[Y";
try{ $,#,yl ol
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); J&jig?t
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); C!J6"j
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~n`G>Oe3
fileFetch.start(); Oky9GC.a
} 0fU^
catch(Exception e){e.printStackTrace ();} X]AbBzy
} P/ x@N
"Go)t+-
} R22P ol
U&<w{cuA
*r]Mn~3
public static void main(String[] args) Ax"I$6n>
{ XqK\'8]\Mw
new TestMethod(); t4CI+fqy
} PbN"+qM
} &yQM8J~
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