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)); 161IWos
} QL-E4]
for(int i=0;i<nEndPos.length-1;i++) [`1@`5SL-
{ ^,Ft7JAn
nEndPos = nStartPos[i+1]; :7s2M
} B06W(y,3Q>
nEndPos[nEndPos.length-1] = nFileLength; cfHtUv
} VzWH9%w
} '.7ER
2UTmQOm
-LlS9[r0
//启动子线程 1gX$U00:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; k%;oc$0G-3
for(int i=0;i<nStartPos.length;i++) ]'0}fuV
{ <Q_E3lQy/
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 48.4GwL7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1CS\1[E
nStartPos,nEndPos,i); i8=+<d
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I@(3~ Ab
fileSplitterFetch.start(); *~zB{
} $/Llzpvny
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w[u>*I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0 .ck!"h}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \ns} M3
nEndPos = " + nFileLength); _*wlK;`
// fileSplitterFetch[nPos.length-1].start(); :\%ZTBLL
(b7',:_U7
iz27yXHZ~
//等待子线程结束 xQNGlVipZ@
//int count = 0; p,3}A(>
//是否结束while循环 352RJC
boolean breakWhile = false; Dp?lgw
,S&p\(r.
4!-/m7%eF
while(!bStop) ah#jvp
{ :bqUA(k
write_nPos(); "XU)(<p
Utility.sleep(500); L$@qEsO
breakWhile = true; c7]0>nU;
m-Qy6"eW
Xj<xen(
for(int i=0;i<nStartPos.length;i++) }eSrJgF4M
{ jEL"Q?#
if(!fileSplitterFetch.bDownOver) ((6?b5[
{ {v2[x W
breakWhile = false; EU'P U
break; `KieN/d%
} m~gcc
} ?BU?c:"f
if(breakWhile) oKPG0iM:
break; 8k^1:gt^
UTO$L|K
r<DPh5ReY
//count++; 2|${2u`$&y
//if(count>4) =0>[-:Z
// siteStop(); R=S)O.*R
} k8,s<m
~NIqO4 D
_D8:p>=
System.err.println("文件下载结束！"); OUy}1%HY
} 96%N
catch(Exception e){e.printStackTrace ();} "7w=LhzV[$
} ?v&2^d4C*F
-gv[u,R
LRSt >; M
//获得文件长度 L#N]1#;
public long getFileSize() *56q4\1
{ Nh^q&[?
int nFileLength = -1; {z@a{L:SC
try{ eRg;)[#0>$
URL url = new URL(siteInfoBean.getSSiteURL()); U/-|hfh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R+9 hog
httpConnection.setRequestProperty("User-Agent","NetFox"); :DFtH13qO
SOluTFxUw
)IKqO:@
int responseCode=httpConnection.getResponseCode(); 4H`B]Zt7
if(responseCode>=400) CW,|l0i
{ e_3B\59k
processErrorCode(responseCode); \OkJX_7
return -2; //-2 represent access is error !4$-.L)#
} ]!2[kA-
4Dasj8GsV
pJ/{X=y
String sHeader; <,JO
u`pw'3hY
[+qB^6I+P%
for(int i=1;;i++) rfV{+^T;
{ B+2.:Zn6
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2>m"CG
//Utility.log(in.readLine()); ;6`7 \
sHeader=httpConnection.getHeaderFieldKey(i); 1{G@'#(
if(sHeader!=null) k.\4<}
{ 4Td)1~zc3
if(sHeader.equals("Content-Length")) !)(To
{ ,t39~w
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Sb`SJ):x
break; M%5_~g2n'\
} [o.#$(
} X&A2:A 6\+
else AH^'E
break; 6df`]sc
} o}yA{<"
} |oR#j `
catch(IOException e){e.printStackTrace ();} Iv?1XI=
catch(Exception e){e.printStackTrace ();} NFI~vkk'G
7Kti&T
a)!R4
Utility.log(nFileLength); (mx}6A
!ozHS_
2]H?q!l!O
return nFileLength; hAD gi^
} %4w#EbkSS
?]>;Wr
R_#k^P^
//保存下载信息（文件指针位置） ,n$HTWa@0
private void write_nPos() \4uj!LgTb
{ P,k=u$
try{ ngzQVaB9
output = new DataOutputStream(new FileOutputStream(tmpFile)); dDl_Pyg4K
output.writeInt(nStartPos.length); @`HW0Y_:
for(int i=0;i<nStartPos.length;i++) U \jFB*U
{ 0VIR=Pbp
// output.writeLong(nPos); |C7=$DgwY
output.writeLong(fileSplitterFetch.nStartPos); % xBQX
output.writeLong(fileSplitterFetch.nEndPos); }1NNXxQ
} ;s5JYR
output.close(); \3O1o#=(
} ,N8SP 'R
catch(IOException e){e.printStackTrace ();} yg"FF:^T
catch(Exception e){e.printStackTrace ();} }L>0}H
} 9dp1NjOtAc
3&B- w
(>gb9n
//读取保存的下载信息（文件指针位置） <M\#7.](
private void read_nPos() 3*eS<n[uG
{ E-#C#B
try{ b3q&CJ4|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %\!@$]3q
int nCount = input.readInt(); o1[[!~8e
nStartPos = new long[nCount]; HyIyrUrYW
nEndPos = new long[nCount]; `Nv7c{M^
for(int i=0;i<nStartPos.length;i++) mA5sK?W
{ \Lm`jU(:l
nStartPos = input.readLong(); "f-HOd\=
nEndPos = input.readLong(); M?I^`6IOc8
} {ApjOIxk
input.close(); H2CpZK'
} V|pO";%>,
catch(IOException e){e.printStackTrace ();} Q=^TKsu
catch(Exception e){e.printStackTrace ();} #X0Y8:vj
} 1c4:'0
%5j*e
Y5<W"[B!
private void processErrorCode(int nErrorCode) :%IB34e
{ ^-(DokdBn
System.err.println("Error Code : " + nErrorCode); 8#RL2)7Uy`
} `|4k>5k
`Cz_^>]|=
UFyk%#L
//停止文件下载 iO}KERfU
public void siteStop() 1}OM"V
{ @Z Dd(xB&
bStop = true; _BG7JvI
for(int i=0;i<nStartPos.length;i++) ~zQxfl/
fileSplitterFetch.splitterStop(); Y$W)JWMY`
[!`5kI
Zl?9ibm;@
} , jCE hb
} kk}_AZ0eK
//负责部分文件的抓取 l_P90zm39!
**FileSplitterFetch.java U"L-1]L
*/ BxB B](
package NetFox; lDZ~
l_zTpyOZ
BVS SO's
import java.io.*; >txeo17Ba\
import java.net.*; b T** y?2
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p,7?rI\N
public class FileSplitterFetch extends Thread { ~\ v"xV
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d5n>2iO
String sURL; //File URL lF\2a&YRbn
long nStartPos; //File Snippet Start Position |?ZNGPt
long nEndPos; //File Snippet End Position ?)7UqVyq
int nThreadID; //Thread's ID 2fP;>0?
boolean bDownOver = false; //Downing is over Ij:yTu
boolean bStop = false; //Stop identical N: 5 N}am
FileAccessI fileAccessI = null; //File Access interface l$m}aQ%h
7hT@,|(j
NdC5w-WY
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j)#GoU=w
{ }U|Vpgd!
this.sURL = sURL; mBQpf/PG
this.nStartPos = nStart; Nf}i/
this.nEndPos = nEnd; SA?1*dw)
nThreadID = id; =D)ADZ\<r
fileAccessI = new FileAccessI(sName,nStartPos);//定位 N\Ab0mDOV.
} z</^qy
0R}hAK+| 4
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public void run() ul!q)cPb{
{ X#o;`QM
while(nStartPos < nEndPos && !bStop) _.SpU`>/f
{ [<nd+3E
)-25?B
`tl-] ^Y2
try{ fP llN8n
URL url = new URL(sURL); qf{HGn_9~1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mv(/M t
httpConnection.setRequestProperty("User-Agent","NetFox"); ^grDP*;W
String sProperty = "bytes="+nStartPos+"-"; UkC'`NWF*
httpConnection.setRequestProperty("RANGE",sProperty); *T:jR
Utility.log(sProperty); m",G;VN
N[N4!k )!$
."`||@|
InputStream input = httpConnection.getInputStream(); 7t+H94KG7
//logResponseHead(httpConnection); h7AO5"6
8tzL.P^
a>k9& w
byte[] b = new byte[1024]; yGH')TsjD
int nRead; \8USFN~(Y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Is9.A_0h
{ 38%"#T3#
nStartPos += fileAccessI.write(b,0,nRead); CiTWjE?|7
//if(nThreadID == 1) 9fsc>9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z 4c^6v
} F1p|^hYDW
L+0:'p=
n%!50E6*:
Utility.log("Thread " + nThreadID + " is over!"); %1)JRc
bDownOver = true; zbfe=J4c
//nPos = fileAccessI.write (b,0,nRead); .`oKd@I*"
} j?VHR$
catch(Exception e){e.printStackTrace ();} V(Oi!(H;v
} }d@;]cps
} S`vw<u4t
He&A>bA)z
V>ZDJW"G!
//打印回应的头信息 rw?wlBEG%
public void logResponseHead(HttpURLConnection con) 8yM8O #S
{ ?F~0\T,7
for(int i=1;;i++) jH<,dG:{
{ &iT^IkA{
String header=con.getHeaderFieldKey(i); 4v2JrC;
if(header!=null) 5Hs!s+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2FGCf} ,
Utility.log(header+" : "+con.getHeaderField(header)); ?i}wm`
else *=77|Dba
break; m;S%RB^~H
} Yx](3w ID
} `!ZkWF6
1 K]
kqGydGh*"
public void splitterStop() u3sr"w&
{ |V^f}5gd
bStop = true; l I2UpfkBP
} l>)+HoD
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|WW'qg]Uu
} OOYdrv,
Vc+~yh.)
;}k_
/* i'}"5O+
**FileAccess.java N5b&tJbM0
*//文件访问(定位，写) N8X)/W
package NetFox; n%s$!R-\
import java.io.*; 2(R{3E4.
g^^^fKUp)
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public class FileAccessI implements Serializable{ 5,R<9FjW
x(rl|o
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 GD!!xt
RandomAccessFile oSavedFile; +:u &]
long nPos; NSQ)lSW,;
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Qd}h:U^
public FileAccessI() throws IOException '(8} <(%
{ ryTtGx%a
this("",0); D?"Q)kVuD
} uFaT~ 4
T? ,Q=.
Ub[UB%(T
public FileAccessI(String sName,long nPos) throws IOException OO;I^`Yn
{ |2I p*
oSavedFile = new RandomAccessFile(sName,"rw"); =E&1e;_xlE
this.nPos = nPos; e(9K.3@{
oSavedFile.seek(nPos); e{.P2rnh
} xP 3>8Y
SnoEi~Da
,;yaYF6|/
public synchronized int write(byte[] b,int nStart,int nLen) t<cWMx5ra
{ j0S[JpoF
int n = -1; ZOL#Q+U
try{ 1c`Yn:H^
oSavedFile.write(b,nStart,nLen); Ua+Us"M3}
n = nLen; >8injW352
} 8vUq8[[
catch(IOException e) "p&4Sn3T2?
{ Dj w#{WR
e.printStackTrace (); CDDEWVd
} _Fjax
Hlj3z3
M2nZ,I=l
return n; 'A/f>W
} x^ sTGd
:kucDQE({?
Qq\hD@Z|
} U"K%ip:Wd
+b{tk=Q:
&9xcP.3
/* 6Q`7>l.|?
**SiteInfoBean.java 9A}nZ1Y
*/ 83Fmu/(
package NetFox; d^`n/"Ice
X&,a=#C^
5WI0[7
public class SiteInfoBean { pwV{@h!
D+*_iM6[-
K Z0%J5
private String sSiteURL; //Site's URL >n>gX/S<C
private String sFilePath; //Saved File's Path 6!RKZj)
private String sFileName; //Saved File's Name 8HdjZ!
private int nSplitter; //Count of Splited Downloading File ,m)YL>k
~uJO6C6A
9tB:1n}
public SiteInfoBean() 'zQp64]F
{//nSplitter的缺省值为5 Y>K3.*.
//default value of nSplitter is 5 ;*e$k7}F
this("","","",5); I0sw/,J/Z
} 8FBXdk?A
wQX%*GbL2
0f,Ii_k bT
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \Qz
{ 7[(<t+
sSiteURL= sURL; G3t\2E9S
sFilePath = sPath; `R:HMO[ow
sFileName = sName; 1@Rl^ey
this.nSplitter = nSpiltter; 2}.EFQp+
~Yl%{1
o]0\Km
} M\=/i\-
/^Zgv-n
0+_:^z
public String getSSiteURL() yzz(<s:o/
{ )H<F([Jri
return sSiteURL; wU5= '
} QBTjiaYGa'
Fpntd IU
X6o iOs
public void setSSiteURL(String value) ['@R]Si"!
{ efm#:>H
sSiteURL = value; Qs\!Kk@
} [\)irCDv
uh~,>~a|
$:*/^)L
public String getSFilePath() *iujJi
{ ]q@W(\I
return sFilePath; MJ`BlE,Fmb
} zY\MzhkX,
| PzXN+DW
6s&%~6J,
public void setSFilePath(String value) {i:Ayhq~&
{ +q)B4A'J!
sFilePath = value; 'M3V#5l)@|
} SWMi+)
qISzn04
I$1~;!<
public String getSFileName() #jX%nqMxW
{ {b26DKkQS
return sFileName; Kv6#WN~
} +FtL_7[v
m-}6DN
ZbLN:g}
public void setSFileName(String value) _iW-i
{ O.wk*m!9
sFileName = value; -'::$ {
} )Xd2qbi
{#uf#J|
5\P3JoH:Yg
public int getNSplitter() ~er4w+"
{ OwG:+T_
return nSplitter; (Qz| N
} 8nHFNOv6
9y5nG
ewzZb*\
public void setNSplitter(int nCount) mi$*,fz
{ ~JxAo\2i
nSplitter = nCount; #kL4Rm;
} isV9nWo$
} aT%6d@g
bY7~b/
.eM A*C~n
/* X4:SH>U!
**Utility.java uOnyU+fZV
*/ +#0,2wR#
package NetFox; ttC+`0+H
=;@?bTmqD
dnUiNs8
public class Utility { d(j|8/tpA
9mfP9
ixIfJ
public Utility() Xu#K<#V
{ L#NW<T
X|X~|&j
vd!|k5t[d
} $Xr9<)?,
]{'lV~fc
//线程睡眠 E7UYJ)6]
public static void sleep(int nSecond) Qg4g(0E@
{ %.;`0}b
try{ K=X13As_
Thread.sleep(nSecond); NKS-G2Y<P
} ^J$?[@qD
catch(Exception e) / qo`vk A
{ [P?.(*
e.printStackTrace (); [ZkK)78}k
} [X|KXlNfm
} !^<%RT9@|
}X[wWH
//日志 ^N_?&pgy
public static void log(String sMsg) [EU\-
{ X7gtR|[
System.err.println(sMsg); J`x!c9zg7
} t|y`Bl2
$6p|}<u
G Za<
public static void log(int sMsg) Y>: e4Q
{ p[M*<==4
System.err.println(sMsg); F),wj8#~>-
} O*zF` 9
} fA>FU/r
#'jd.'>
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/* > : ;*3
**TestMethod.java SH${\BKup
*/ SvD^'( x
package NetFox; m6=Jp<
=ADdfuKN
L 2:N@TP
public class TestMethod { RTR@p =ck
)w3HC($g
5L8)w5
public TestMethod() El)WjcmH
{ ///xx/weblogic60b2_win.exe G*lkVQ6?
try{ SYsbe 5j
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); C%y!)v_x
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); QL4BD93v
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,>Lj>g{~
fileFetch.start(); RRH[$jk
} Y"&1jud4xl
catch(Exception e){e.printStackTrace ();} hB)TH'R{:
M} {'kK
3\jcq@N
} 2XN];,{
D-IXO@x
0cBk/x^s
public static void main(String[] args) X}s}E ;v9
{ Y +9OP
new TestMethod(); j\S}TaH0e
} };=44E'7
} CnA0^JX
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