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)); Hs`#{W{.
} S}p&\w H
for(int i=0;i<nEndPos.length-1;i++) ];{l$-$$
{ ':2*+
nEndPos = nStartPos[i+1]; "tz0ko,(
} GgpQ]rw
nEndPos[nEndPos.length-1] = nFileLength; 3|'#n[3
} C(1A8
} am'p^Z@
;'Vipj
!%RJC,X
//启动子线程 $L&9x3+?Kg
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; uM#U!
for(int i=0;i<nStartPos.length;i++) bHQKRV
{ cH*/zNp
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), id#k!*$7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Z>w^j.(
nStartPos,nEndPos,i); j zmSFKg*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ",aT<lw.
fileSplitterFetch.start(); 1nlE3Y?AV
} ;LF)u2x=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2) /k`Na
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); '^oGDlkr H
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^;CR0.4
nEndPos = " + nFileLength); |p8"9jN@}c
// fileSplitterFetch[nPos.length-1].start(); [`zbf_RyO
rMXOwkE
S`2mtg
//等待子线程结束 {Z?$Co^R
//int count = 0; ll<9f)
//是否结束while循环 8W1K3[Jj<
boolean breakWhile = false; hV>4D&<
e1 {t0f
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while(!bStop) AK~`pq[.
{ %];h|[ax]
write_nPos(); g@k#J"Q'[
Utility.sleep(500); hk5E=t~&
breakWhile = true; az\<sWb#
\%-E"[!
].k+Nzf_
for(int i=0;i<nStartPos.length;i++) oXQ<9t1(
{ +C'TW^
if(!fileSplitterFetch.bDownOver) j2o1"
{ 2<6`TA*m
breakWhile = false; 20.-;jK
break; u6iU[5
} nI`f_sp
} !Ig|m+
if(breakWhile) v ]/OAH6D
break; *gM,x4Y
~$&:NB1~q
'#,e @v
//count++; s.R-<Y3
//if(count>4) |b$>68:
// siteStop(); }XGMa?WR
} cQ3W;F8|n
eq@am(#&kY
G%P>Ag
System.err.println("文件下载结束！"); =9qGEkd3
} QQg8+{>
catch(Exception e){e.printStackTrace ();} :mXGIRi
} 3d*&':
7SgweZ}"
KA5~">l
//获得文件长度 ~ON1Zw[+
public long getFileSize() ia%z+:G
{ <*s"e)XeqF
int nFileLength = -1; ||-nmOy
try{ v229H<
URL url = new URL(siteInfoBean.getSSiteURL()); Y7<zm}=(/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Zg -]sp]
httpConnection.setRequestProperty("User-Agent","NetFox"); s<[A0=LH
qP~WEcH`[
'|vD/Qf=&
int responseCode=httpConnection.getResponseCode(); gM4Pj[W
if(responseCode>=400) =N YgGEFq.
{ :J^qjAV
processErrorCode(responseCode); )y9;OA
return -2; //-2 represent access is error bA}AD`5
} FJP< bREQ
Z[",$Lt
`I5O4|K)
String sHeader; K(<$.
"-w^D!C
D`6iDit
for(int i=1;;i++) ')B =|T)
{ WfTD7?\dw
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6X/wdk
//Utility.log(in.readLine()); f|OI`
sHeader=httpConnection.getHeaderFieldKey(i); 8wr8:(Y$
if(sHeader!=null) H&M1>JtE
{ PU W[e%
if(sHeader.equals("Content-Length")) ]eE 1n2
{ #~L!pKM
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &5?G-mn
break; 3y99O $EAc
} 3UdU"d[75
} bmu6@jT
else 8".2)W4*
break; ~W<CE_/]k
} 2nv[1@M
} cFK @3a
catch(IOException e){e.printStackTrace ();} IV'p~t
catch(Exception e){e.printStackTrace ();} nZfs=@w:y
;B~P>n}}_]
<47k@Ym
Utility.log(nFileLength); w/W7N
#)o7"PW:
k;k}qq`d
return nFileLength; K/txD20 O|
} W^es;5
4:7mK/Z
`0{ S3v
//保存下载信息（文件指针位置） _T5)n=|
private void write_nPos() b O=yi)
{ !nd*W"_gQ/
try{ $IVwA
output = new DataOutputStream(new FileOutputStream(tmpFile)); oKA&An
output.writeInt(nStartPos.length); /)EY2Y'
for(int i=0;i<nStartPos.length;i++) 0w %[
{ P`S@n/}
// output.writeLong(nPos); <xo-Fv
output.writeLong(fileSplitterFetch.nStartPos); DIaYo4
output.writeLong(fileSplitterFetch.nEndPos); pu+ur=5&
} ~=En+J}*
output.close(); rkB'Hf
} ";x+1R.d
catch(IOException e){e.printStackTrace ();} A(8n
catch(Exception e){e.printStackTrace ();} -)jax
} +/rH(Ni
~6aCfbu%V
RO&H5m r%@
//读取保存的下载信息（文件指针位置） 4-R^/A0
private void read_nPos() jjzA .8?(7
{ !TKkec8$
try{ `_vB+a
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); P[ r];e
int nCount = input.readInt(); id^sr Mw
nStartPos = new long[nCount]; $w#r"= )
nEndPos = new long[nCount]; j(rL
for(int i=0;i<nStartPos.length;i++) Km#pX1]>e
{ UPiW73Nu
nStartPos = input.readLong(); jS.g]k
nEndPos = input.readLong(); e@#kRklV&
} FLZWZ;
input.close(); G:W>I=^DaR
} BvD5SBa}"
catch(IOException e){e.printStackTrace ();} _>m-AI4^
catch(Exception e){e.printStackTrace ();} j*v40mXl`2
} px;/8c-
@}-r&/#
Z8#Gwyinx
private void processErrorCode(int nErrorCode) '8Ztj
{ ~EzaC?fQ
System.err.println("Error Code : " + nErrorCode); 6K`c/)
} ;%C'FV e]
Q/ms]Du
fBn"kr;
//停止文件下载 {c?JuV4q?
public void siteStop() lv&mp0V+
{ M:KbD|
bStop = true; gi/@j
for(int i=0;i<nStartPos.length;i++) ^ KK_qC
fileSplitterFetch.splitterStop(); Ys+OB*8AE
?~"bR%
rl#vE's6.e
} #11NPo9
} kum#^^4G|
//负责部分文件的抓取 |BT MJ:B
**FileSplitterFetch.java ^9OUzTF
*/ aNn"X y\ k
package NetFox; :2 >hoAJJ
%3q0(Xl
)n49lr6X
import java.io.*; 0P^L}VVX
import java.net.*; Wz4&7KYY
Pi,QHb`>
?[<Tx-L
public class FileSplitterFetch extends Thread { p.I.iAk%G^
n\Fp[9+Z\
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String sURL; //File URL &cWjEx
long nStartPos; //File Snippet Start Position )#|<w9uec
long nEndPos; //File Snippet End Position -K,-h[o
int nThreadID; //Thread's ID DFhXx6]
boolean bDownOver = false; //Downing is over 9Zry]$0~R
boolean bStop = false; //Stop identical >Rvx[`|O!m
FileAccessI fileAccessI = null; //File Access interface 5uq3\a
09A X-JP
%75xr9yOP
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Q9}dHIe1E
{ b" xmqWa
this.sURL = sURL; 8[r9HC
this.nStartPos = nStart; %ms'n
this.nEndPos = nEnd; }X GEX:1K
nThreadID = id; #&v/icz$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8+]hpa,q
} Qk!;M|
]E =Iu
(-]r~Ol^
public void run() x21dku<6K[
{ Y(cN}44
while(nStartPos < nEndPos && !bStop) `1{N=!U(&
{ Rqwzh@}
b:qY gg
LIg{J%
try{ 6wco&7
URL url = new URL(sURL); $$:ZX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ["\;kJ.
httpConnection.setRequestProperty("User-Agent","NetFox"); PoEqurH0
String sProperty = "bytes="+nStartPos+"-"; ikE<=:pe
httpConnection.setRequestProperty("RANGE",sProperty); ih?^t(i
Utility.log(sProperty); `eu9dLzH
0$7.g!h?
Y+K|1r
InputStream input = httpConnection.getInputStream(); %OgS^_tu
//logResponseHead(httpConnection); Bgmn2-
XZw6Xtn
x `V;Y]7'
byte[] b = new byte[1024]; ;3_l@dP"
int nRead; 4v[~r1!V
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ''\;z<v
{ 8kP3+
nStartPos += fileAccessI.write(b,0,nRead); ?\8?%Qk
//if(nThreadID == 1) UT}i0I9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k6=nO?$
} ;S xFp
lO2[JP
#+$Q+Z|6k
Utility.log("Thread " + nThreadID + " is over!"); OFje+S
bDownOver = true; |yo\R{&6
//nPos = fileAccessI.write (b,0,nRead); )Ud-}* g
} pLv$\MiZ
catch(Exception e){e.printStackTrace ();} HHqwq.zIy
} $=?@*p
} +l=r#JF
dL|+d:v
#97h6m?
//打印回应的头信息 'l,V*5L
public void logResponseHead(HttpURLConnection con) h$L"8#
{ VY)s+Bx
for(int i=1;;i++) \@&_>us
{ %e&9.
String header=con.getHeaderFieldKey(i); %v2R.?F8
if(header!=null) F[ewn/]n
//responseHeaders.put(header,httpConnection.getHeaderField(header)); soCi[j$lH
Utility.log(header+" : "+con.getHeaderField(header)); G9JAcO1
else {\[5}nV
break; 1yqJwy;X
} ytNO*XoR
} -(K9s!C!.
%u;~kP|S%
D-N8<:cA
public void splitterStop() E@Ad'_H
{ 41SGWAd#:
bStop = true; z5TuGYb<
} H:"maS\I
*{+G=d
sN5B7)Vc
} YtO|D
[LRLJ_~g5
`mN4_\]
/* 8zMu7,E
**FileAccess.java [|l?2j\
*//文件访问(定位，写) jMpD+Mb
package NetFox; rSrIEP,c'
import java.io.*; 36am-G
VWO9=A*Y|
)Y)pmjZaG
public class FileAccessI implements Serializable{ f47M#UC
~/*MY
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Onwp-!!.
RandomAccessFile oSavedFile; 8n>9;D5n
long nPos; r7',3V
B,{K*-7)MX
7k8pZ
public FileAccessI() throws IOException <qGu7y"
{ 7NJhRz`_
this("",0); L5,NP5RC
} Qf@
>KJ+-QuO&
H<3I 5Kgt
public FileAccessI(String sName,long nPos) throws IOException 50={%R
{ ,{c?ymw?
oSavedFile = new RandomAccessFile(sName,"rw"); 73){K?R
this.nPos = nPos; f;b[w
oSavedFile.seek(nPos); YIjTL!bA"
} ]9@F~)
/E\%>wv
RU\/j%^
public synchronized int write(byte[] b,int nStart,int nLen) 4]E3cAJ
{ %VnbmoO
int n = -1; bcYF\@};
try{ s)pbS}L
oSavedFile.write(b,nStart,nLen); $ , u+4h
n = nLen; eow'K 821A
} 8e(\%bX
catch(IOException e) r3PT1'P?L
{ m|G'K[8
e.printStackTrace (); is-7 j7;
} GmP@;[H"
.;N1N^
\*<d{gZ~
return n; H/37)&$E(
} qXwPDq/
BSVxN
- RU=z!{
} zld#qG6
eYvWZJa4
IqoR7ajA
/* uu>Pkfo
**SiteInfoBean.java k1D@fiz
*/ $F5 b
package NetFox; ;67x0)kn
*vwbgJG! *
|mw.qI|
public class SiteInfoBean { Zo~
+O?KNZ
jIyB
private String sSiteURL; //Site's URL "L&#lfOKG
private String sFilePath; //Saved File's Path (O(}p~s
private String sFileName; //Saved File's Name ybKWOp:O
private int nSplitter; //Count of Splited Downloading File @pRlxkvV
XLrwxj0
,1+y/{S
public SiteInfoBean() 9j6QX~,
{//nSplitter的缺省值为5 1^}[&ar
//default value of nSplitter is 5 ia+oX~W!VR
this("","","",5); {C N~S*m
} ?b>,9A.Z
U ^5Kz-5.
A"dR{8&0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +Z!)^j
{ ^Dn D>h@q
sSiteURL= sURL; HOJs[mqB%
sFilePath = sPath; 2$g6}A`r
sFileName = sName; _8F`cuyW
this.nSplitter = nSpiltter; CU@Rob}s
%D%8^Zd_
&&8IU;J
} ?!d&E?9\
m!tbkZHQn0
nz=GlO'[
public String getSSiteURL() p;3O#n-_
{ TE7nJ gm
return sSiteURL; P"IPcT%Ob%
} 2j}\3Pi
bU2Z[sn.
J$GUB3 G
public void setSSiteURL(String value) RL@VSHXc
{ ;RC{<wBTx
sSiteURL = value; IYS)7`{]
} WrxP
,*&:2o_r
O7-mT8o
public String getSFilePath() %7IugHH9y
{ BW}U%B^.
return sFilePath; @hiCI.?X
} C'.L20qW
mGJKvJF
*rs5]U<
public void setSFilePath(String value) j<VFn~*_
{ 93("oBd[s(
sFilePath = value; bYpntV
} jjw`Dto&
F;4vPbH+
;=eDO(Ij
public String getSFileName() )_syZ1j
{ aeFe!`F
return sFileName; A+ZK4]xb
} fTS5yb%
A}G7l?V&
&C,'x4c"
public void setSFileName(String value) dx5#\"KX=,
{ U@_dm/;0&
sFileName = value; #%iDT6
} NO "xL,
0%&1\rm+j
wSzv|\ G
public int getNSplitter() y~AVei&
{ X^}I-M%{m
return nSplitter; =9y[1t
} E4`N-3
]qethaNy
L-jJg,eY
public void setNSplitter(int nCount) jaTh^L
{ H[s(e56z
nSplitter = nCount; >Ea8G,
} :~b3^xhc^
} [;4g
>BIMi^
T6O::o6
/* 1-%fo~!l
**Utility.java "Gfh,e
*/ lP[w?O
package NetFox; yzbx .
wa<MRt W=
"cE7 5
public class Utility { 3c#BKHNC
A>vBQN
nW PF6V>
public Utility() =e/9&993
{ 7,U=Qe;
7]U"Z*
aGrIQq/k)%
} Sz%tJD..
(7mAt3n k
//线程睡眠 )JDs\fUE
public static void sleep(int nSecond) dbwe?ksh
{ Jv>gwV{
try{ iQ tNAj
Thread.sleep(nSecond); Lz`E;k^
} #zG&|<hc
catch(Exception e) l Q'I
{ 5QW=&zI`=
e.printStackTrace (); nG,A@/N
} :Ux?,
} @GBxL*e
|XT)QK1
//日志 nim*/LC[:
public static void log(String sMsg) o>).Cj
{ T_s_p
System.err.println(sMsg); 6TQoqH8@U
} Vr)<\h
Lrta/SU*
Vu)4dD!
public static void log(int sMsg) E[2m&3&
{ NE"@Bk cm
System.err.println(sMsg); G^~k)6v=m
} `e(c^z#
} aUzBV\Yd}
{v=T [D
_a5d?Q9Z
/* iWRH{mK
**TestMethod.java ~rlB'8j(
*/ $Wjww-mx
package NetFox; >/:" D$
y-T| #
jq-p;-i
public class TestMethod { iWei
fdxLAC
AuUde$l_
public TestMethod() `NnUyQ;T
{ ///xx/weblogic60b2_win.exe *v;!-F&8>
try{ ,oN8HpGs
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $$D}I*^Dt
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !,l9@eJQ
SiteFileFetch fileFetch = new SiteFileFetch(bean); n1qQ+(xC
fileFetch.start(); iocI:b<
} NS9B[*"Jl
catch(Exception e){e.printStackTrace ();} kd=GCO
kQ4dwF~
k]W[`
} b^ L \>3
YsG%6&zEq
&Flglj~7l
public static void main(String[] args) \qR7mI/*
{ -mC0+}h
new TestMethod(); X- pqw~$
} /+8JCp
} $i&e[O7T;
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