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)); eZ"1gYqy
} Bgmn2-
for(int i=0;i<nEndPos.length-1;i++) iC iZJ"
{ RwS@I/
nEndPos = nStartPos[i+1]; T~h5B(J;
} "c}@V*cO<d
nEndPos[nEndPos.length-1] = nFileLength; 5*[2yKsTi
} 7ugZE93!
} (KvROV);
&uC@|dbC5
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//启动子线程 eNiaM6(J
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `jST
for(int i=0;i<nStartPos.length;i++) ?\8?%Qk
{ j~j\\Y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hHqh{:q{v
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), G,;,D9jO7
nStartPos,nEndPos,i); EyY.KxCB
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wP,JjPUt
fileSplitterFetch.start(); fDx9iHGv
} Mi~(aah
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eT2*W$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); qRbf2;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", h*u`X>!!
nEndPos = " + nFileLength); iAa;6mH
// fileSplitterFetch[nPos.length-1].start(); "`6n6r42
(H+'X}1
\.mI
//等待子线程结束 A.UUW
//int count = 0; a<]B B$~
//是否结束while循环 g/13~UM\
boolean breakWhile = false; I(=V}s2
Vf(6!iRP@
Z,iHy3`
while(!bStop) 0a"igq9t
{ ioPUUUb)
write_nPos(); <3,<\ub
Utility.sleep(500); BB|?1"neg
breakWhile = true; VY)s+Bx
Nan[<
DNP13wp@
for(int i=0;i<nStartPos.length;i++) y^o@"IYu3
{ If%/3UJ@
if(!fileSplitterFetch.bDownOver) [@4rjGwB
{ zSb PW6U
breakWhile = false; -GLMmZJt
break; G9JAcO1
} svXR<7)#
} ?k(\ApVHj
if(breakWhile) dK>7fy;mv
break; i*CZV|t US
?.Pg\ur
]r_;dYa
//count++; aM4k *|H?
//if(count>4) z2Z^~,i
// siteStop(); 7=(Hy\Q5xH
} a'\o7_
Mfv1Os:ST
t|m=J`a{q;
System.err.println("文件下载结束！"); q{+_ <2U|
} 10H)^p%3+
catch(Exception e){e.printStackTrace ();} {/pm<k=
} ;NRF=d>
d|4}obCt
`O'`eY1f
//获得文件长度 3MRc4UlB
public long getFileSize() Y3O#Q)-j$
{ fxT-j s#S
int nFileLength = -1; %w7]@VZ
try{ I[n^{8gz
URL url = new URL(siteInfoBean.getSSiteURL()); UT="2*3gz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S]E.KLR?[;
httpConnection.setRequestProperty("User-Agent","NetFox"); ur$l Z0
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int responseCode=httpConnection.getResponseCode(); t'ZWc\
if(responseCode>=400) H<1WbM:w
{ S6[v;{xJ
processErrorCode(responseCode); 36am-G
return -2; //-2 represent access is error MeUaTJFEB
} @}kv-*
*_?dVhxf
0:b2(^]bg
String sHeader; H8"@iE,
f47M#UC
zhf.NCSt(
for(int i=1;;i++) R"K#7{p9
{ f^VP/rdg
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); KgR<E
//Utility.log(in.readLine()); 8n>9;D5n
sHeader=httpConnection.getHeaderFieldKey(i); MQ"xOcD*F
if(sHeader!=null) +5XpzZ{#Wa
{ p ]d]QMu
if(sHeader.equals("Content-Length")) ~9j%Hm0ht
{ -I=l8m6L
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !>1@HH?I\/
break; <qGu7y"
} y{N-+10z
} {P*m;a`}
else |7zd%!
break; 3$X'Y]5a
} HbW0wuI
} '}$Dgp6e
catch(IOException e){e.printStackTrace ();} G\(|N9^:
catch(Exception e){e.printStackTrace ();} 8(* [Fe9
F8apH{&t
50={%R
Utility.log(nFileLength); 2p"WTd
p/h Rk<K6
4R\Hpt
return nFileLength; \eFR(gO+
} [Jv@J\
#t+d iR
KGg3 !jY
//保存下载信息（文件指针位置） g1(IR)U!z
private void write_nPos() RU\/j%^
{ LGtIm7
try{ k1!@^A
output = new DataOutputStream(new FileOutputStream(tmpFile)); Sy 'Dp9!|
output.writeInt(nStartPos.length); o>VVsH
for(int i=0;i<nStartPos.length;i++) G["c\Xux
{ w`5xrqt@
// output.writeLong(nPos); s)pbS}L
output.writeLong(fileSplitterFetch.nStartPos); Sm5H_m!
output.writeLong(fileSplitterFetch.nEndPos); ' MxrQ;|S
} ,S!azN=
output.close(); }+sT4'Ah>
} F|!){=
catch(IOException e){e.printStackTrace ();} 1@-Ns
catch(Exception e){e.printStackTrace ();} <%"b9T`'
} hq #?kN
\o^2y.q:>
G nG>7f[v
//读取保存的下载信息（文件指针位置） qo|WXwP2
private void read_nPos() =y-@AU8
{ $b mLu=9
try{ a0#J9O_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (I./ Uu%
int nCount = input.readInt(); }1upi=+aE
nStartPos = new long[nCount]; 1aTB%F
nEndPos = new long[nCount]; :*KHx|Q
for(int i=0;i<nStartPos.length;i++) L'kmNVvYN
{ U-3i
nStartPos = input.readLong(); w.TuoWo>
nEndPos = input.readLong(); =z /dcC$r
} @!1x7%]G
input.close(); 8#g1P4
} BT"XT5@
catch(IOException e){e.printStackTrace ();} PAM}*'
catch(Exception e){e.printStackTrace ();} ^RI?ybDd
} u`RI;KF~F
s']Bx=
$A-J,_:T<
private void processErrorCode(int nErrorCode) B]l)++~
{ \vO,Ee~#W
System.err.println("Error Code : " + nErrorCode); 5yz(>EVH
} _BP&n
uwy:t!(j
p|p l
//停止文件下载 ^\S~?0^m
public void siteStop() Ug<#en
{ qO|R^De
bStop = true; !/]WrGqbS
for(int i=0;i<nStartPos.length;i++) |mw.qI|
fileSplitterFetch.splitterStop(); =UfsL%
XSyHk"g`
?o|f':
} e0,|Wm
} q}?4f*WC
//负责部分文件的抓取 O[ef#R!
**FileSplitterFetch.java Fkd+pS\9g~
*/ %Da1(bBh
package NetFox; WL"^>[Vq
jr:7?8cH0L
_y} T/I9
import java.io.*; bl&nhI)w
import java.net.*; P&^;656r
wLnf@&jQ%
9eQxit7
public class FileSplitterFetch extends Thread { dx@-/^.
y#z
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String sURL; //File URL (bH`x]h#
long nStartPos; //File Snippet Start Position gq'Y!BBQy
long nEndPos; //File Snippet End Position #ZrHsfP
int nThreadID; //Thread's ID HK0!P*
boolean bDownOver = false; //Downing is over YOmM=X+'H
boolean bStop = false; //Stop identical 7Bd-!$j+
FileAccessI fileAccessI = null; //File Access interface KJaXg;,H
yj.7'{mA
!`Hd-&}bYz
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException fy@<&U5rg
{ %2{%Obp'
this.sURL = sURL; |#cm`v
this.nStartPos = nStart; =V-|#j
this.nEndPos = nEnd; TI,&!E?;
nThreadID = id; FwkuC09tI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 HOJs[mqB%
} Ku}Z
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gL*>[@RO
public void run() _8F`cuyW
{ aGtf z)
while(nStartPos < nEndPos && !bStop) oF1,QQ^dg
{ D!Pq4'd(
_n50C"X=&(
zGkS^Z=(
try{ |8l<$J
URL url = new URL(sURL); @v)p<r^M">
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m4hg'<<V
httpConnection.setRequestProperty("User-Agent","NetFox"); 7>))D'l57
String sProperty = "bytes="+nStartPos+"-"; b)qoh^
httpConnection.setRequestProperty("RANGE",sProperty); Ki$MpA3j
Utility.log(sProperty); &-Gqdnc
Pama#6?OPh
qGB{7-ru
InputStream input = httpConnection.getInputStream(); iW%I|&
//logResponseHead(httpConnection); H2jgO?l;!
nG'&ZjA
3yU.& k
byte[] b = new byte[1024]; (mTE;s(
int nRead; ~O oidKT
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $Y/9SV,
{ 26I_YL,S
nStartPos += fileAccessI.write(b,0,nRead); W_\5nF
//if(nThreadID == 1) c|B.n]Z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !h23cj+V
} IYS)7`{]
{E9+WFz5
mpU$+
Utility.log("Thread " + nThreadID + " is over!"); ,*&:2o_r
bDownOver = true; _u5#v0Y
//nPos = fileAccessI.write (b,0,nRead); $0>60<J
} %7IugHH9y
catch(Exception e){e.printStackTrace ();} K}buH\yco
} T?tgdJ
} #~2%)
7byK{{/z
Cz\ew B
//打印回应的头信息 _/-jX
public void logResponseHead(HttpURLConnection con) 4U+xb>
{ lm-dW'7&
for(int i=1;;i++) P3x= 8_#
{ ' V^6XI
String header=con.getHeaderFieldKey(i); 'MUv5Th
if(header!=null) -pf}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 59Xi3KY
Utility.log(header+" : "+con.getHeaderField(header)); s E2D#D
else 8D3OOab
break; mS$j?>m
} tl,.fjZn
} =[cS0Sy
(|:M&Cna]
vNV/eB8#S
public void splitterStop() `.~N4+SP
{ Rg\z<wPBG
bStop = true; fk6%XO
} A+ZK4]xb
la0BiLzb]
([T>.s
} "d#Y}@*~o
lT(WD}OS
V@e?#iz
/* LrM=*Rh,O
**FileAccess.java DCIxRPw
*//文件访问(定位，写) (C-{B[Y
package NetFox; r3&G)g=u
import java.io.*; |[<_GQl
U@_dm/;0&
%GjM(;Tk
public class FileAccessI implements Serializable{ p{amC ;cI$
=9'RM>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9YIM'q>`v
RandomAccessFile oSavedFile; :~e>Ob[,"
long nPos; R]c+?4J
I5 o)_nc
X$ 0?j1
public FileAccessI() throws IOException u]<,,
{ 5nv#+ap1 "
this("",0); C%$edEi
} :)wy.r;N
bf ]f=;.+
#^lL5=
public FileAccessI(String sName,long nPos) throws IOException L-jJg,eY
{ bhTb[r
oSavedFile = new RandomAccessFile(sName,"rw"); u)X=Qm)
this.nPos = nPos; r?+%?$
oSavedFile.seek(nPos); H*RC@O_hv
} 0%9 q8M;
zT=Ho
j"ThEx0
public synchronized int write(byte[] b,int nStart,int nLen) Y;dz,}re
{ 2iY3Lsna
int n = -1; [YRz*5
try{ ?*[N_'2W+
oSavedFile.write(b,nStart,nLen); /\ y?Y
n = nLen; 3KRd
} b3&zjjQ
catch(IOException e) 9_L[w\P|4
{ |{BIHgMh
e.printStackTrace (); Y}t \4 di
} 1tEgl\u\
wKtl+}}
kw>v:F<M
return n; W]"zctE
} Tzt8h\Q^z
-[*,^Ti`
SN9kFFIPb=
} UldXYtGe
2 Wt> Mi
"9ZID-~]
/* N=4G=0 `ke
**SiteInfoBean.java MW! srTQ_
*/ 7L`A{L
package NetFox; )IP,;<
iZ#!O*>
]{)a,c NG
public class SiteInfoBean { aGrIQq/k)%
9=vMgW
WKts[Z
private String sSiteURL; //Site's URL bZnuNYty75
private String sFilePath; //Saved File's Path ^nT/i .#_
private String sFileName; //Saved File's Name p#01gB
private int nSplitter; //Count of Splited Downloading File 09X01X[
,V,`Jf
#X%~B'
public SiteInfoBean() }6p@lla,%]
{//nSplitter的缺省值为5 PXK7b2fE.
//default value of nSplitter is 5 6_J$UBT
this("","","",5); ^Ew]uN>,
} 8UXjm_B^'
@)UZ@ ~R
8ZM?)#`@{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5m*iE*+
{ K#%&0D!
sSiteURL= sURL; sd,J3
sFilePath = sPath; $h2){*5E{
sFileName = sName; mPOGidxix
this.nSplitter = nSpiltter; K{x\4
g-Mj.owu=
X>1,!I9
} sT !~J4
3VsW@SG7N
WzPTFw[
public String getSSiteURL() -MW_|MG
{ %z/hf
return sSiteURL; ~k\fhx
} zjJ *n8l
9E zj"
j5K]CTz#
public void setSSiteURL(String value) Hc! mB
{ B( ]M&
sSiteURL = value; i'a?kSy
} .\[`B.Q
xAqb\|$^
DwaBdN[!7
public String getSFilePath() OglEt["
{ n)L*
return sFilePath; X>d"]GD
} Q;[,Q~c[u
`e(c^z#
qOe+ZAJ{%N
public void setSFilePath(String value) VeGL)
{ aDq5C-MzG
sFilePath = value; y[`l3;u:'
} _a5d?Q9Z
pf%=h |
!g?|9
public String getSFileName() *?Lv3}E
{ (*Z)(O*z
return sFileName; hLI`If/+K
} W}--p fG
qmnZAk
!2 LCLN\
public void setSFileName(String value) NMW#AZVd
{ jq-p;-i
sFileName = value; DQNnNsP:M-
} 3 *d"B tg
<A[E:*`*
~"!] 3C,L
public int getNSplitter() AuUde$l_
{ Y,GU%[+
return nSplitter; _p#CwExuy
} CKtB-a
0)%YNaskj
P<PJ)>
public void setNSplitter(int nCount) $$D}I*^Dt
{ Ipf|")*
nSplitter = nCount; !,l9@eJQ
} m#8m] Y
} c|lu&}BS
?Y)vGlWDW<
`k=bL"T>\
/* $"`- ^
**Utility.java 3!3xCO
*/ {kp-h2I,
package NetFox; x9$` W
_.>QEh5"5
2{]`W57_=
public class Utility { aiQ>xen5C5
YCdS!&^UN
!zuxz
public Utility() K)-U1JE7
{ aHs^tPg
{n(b{ibl
;6gDV`Twy
} jYx38_5e
-#0qV:D
//线程睡眠 tna .52*/
public static void sleep(int nSecond) @xQgY*f#
{ *n;!G8\
try{ AcS|c:3MUy
Thread.sleep(nSecond); O>qll6]{@
} `D>S;[~S7
catch(Exception e) ~Cl){8o
{ #OBJzf*p
e.printStackTrace (); 6S\C}U/
} >C7r:%
} xgABpikC^
rE iKi
//日志 7x#Ckep:I
public static void log(String sMsg) gG uZ8:f
{ <!L>Exh&r
System.err.println(sMsg); bQE};wM,
} k xP-,MD
uJOJ-5}yt
"XB[|#&
public static void log(int sMsg) 0rh]]kj
{ |w_7_J2
System.err.println(sMsg); WEFlV4/
} 0="%Y^N
} &?VQ,+[<
z|=}1;(.
kV?y0J.
/* 9w"h
**TestMethod.java MA;1;uI,
*/ kz{/(t
package NetFox; "Weg7mc#
+hvO^?4j
`1'6bp`Z
public class TestMethod { &@%W29:
UH]l9Aq$P
TS/.`.gT
public TestMethod() KQacoUHrK?
{ ///xx/weblogic60b2_win.exe e:DkGy`-s
try{ &L#UGp$,
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .zS?9MP
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8*8Zc/{
SiteFileFetch fileFetch = new SiteFileFetch(bean); pF&(7u
fileFetch.start(); pcau}5 .
} !g Z67
catch(Exception e){e.printStackTrace ();} thV>j9'
RMX:9aQ3F
6;C3RU]
} UQ'\7OS
#~SP)Ukp
y|CP;:f;
public static void main(String[] args) Ge,;8N88
{ Xua+cVc\y
new TestMethod(); !vX D
} ^ s1Q*He
} a-l;vDs
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