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)); HD!2|b~@
} eo&^~OVT
for(int i=0;i<nEndPos.length-1;i++) A(}D76o_
{ IlfH
nEndPos = nStartPos[i+1]; '4e, e|r
} Boj#r ,x
nEndPos[nEndPos.length-1] = nFileLength; >hv8zHOO:
} 5KgAY;|
} {YMO8
,vs#(d6G
ArVW2gL
//启动子线程 uWDWf5@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4`zK`bRcK#
for(int i=0;i<nStartPos.length;i++) }CGA)yK~3
{ PfjD!=yS=h
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H84Zg/ ^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), f~P~%
nStartPos,nEndPos,i); 34c+70x7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8z)J rO}
fileSplitterFetch.start(); K)N'~jCG
} 9(pF!}1%\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }P\J?8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); kHz?vVE/l
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", rk8Cea
nEndPos = " + nFileLength); Dj9ecV`
// fileSplitterFetch[nPos.length-1].start(); EV[ BB;eb
E>isl"
Zt ;u8O
//等待子线程结束 zXaA5rZO
//int count = 0; 2ut)m\)/)
//是否结束while循环 .g>0FP
boolean breakWhile = false; XE($t2x,M
$Y?[[>u
fM!@cph(8
while(!bStop) 1qm _Qs&
{ {xu~Dx
write_nPos(); 0lLg uBW@
Utility.sleep(500); l&{+3aC:
breakWhile = true; uFnq3m^u
63HtZ=hO7
]FEsN6
for(int i=0;i<nStartPos.length;i++) [vn"r^P
{ >=K~*$&>
if(!fileSplitterFetch.bDownOver) (Qd@Q,@(s
{ 4Ul*`/d
breakWhile = false; -'rb+<v
break; hh8U/dVk*
} v-&@c
} F@<^
if(breakWhile) "Tnmn@
break; 3U4h>T@s|
Nn{/_QG
Fd/Ra]@\Y
//count++; Rja>N)MzBf
//if(count>4) '#u=wyp
// siteStop(); 0)Q*u
} qk=OodEMK
;nw}x4Y[
H,Yrk(O-
System.err.println("文件下载结束！"); f{+X0Oj
} tvOyT6]
catch(Exception e){e.printStackTrace ();} %`0*KMO3
} $g '4'
[/Xc},HbMe
4XNkto
//获得文件长度 seiE2F[
public long getFileSize() `teaE7^Wm
{ %ZTI ?a
int nFileLength = -1; Lm7fz9F%
try{ ~}g)N
URL url = new URL(siteInfoBean.getSSiteURL()); ?P"j5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xV.UM8
httpConnection.setRequestProperty("User-Agent","NetFox"); ?7dV:]%~2
xcX^L84\
4%*`'o$_
int responseCode=httpConnection.getResponseCode(); CGs5`a
if(responseCode>=400) ,:pKNWY)Q
{ b5?k)s2
processErrorCode(responseCode); PJ2m4ulY
return -2; //-2 represent access is error 7-MyiCt
} kk ZMoK
bYwe/sR
_Kg"l5?B
String sHeader; no9=K4h`
%h}3}p#4
'Ooq.jaK;/
for(int i=1;;i++) #K\;)z(?
{ \ mg
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @!mjjeG+1
//Utility.log(in.readLine()); kY#sQz}8
sHeader=httpConnection.getHeaderFieldKey(i); <ELqj2`c
if(sHeader!=null) O6]X\Cwj%
{ dF'oZQz
if(sHeader.equals("Content-Length")) iCdq-r/r!6
{ 23'Ac,{
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); A?H.EZ
break; aj}#~v1
} hD,@>ky
} [-2Tj)P C
else $o^N_`l
break; k@Bn}r
} #R#|hw
} ]]/p.#oD,
catch(IOException e){e.printStackTrace ();} N[wyi&m4
catch(Exception e){e.printStackTrace ();} oD_#oX5\
M[6WcH0/T
]?V2L`/
Utility.log(nFileLength); 9`G}GU]@}
!uN_<!
T^H`$;\
return nFileLength; *wV`7\@
} Z(hRwIOF
I ka V g L
]lA.?
//保存下载信息（文件指针位置） 6B@{X^6y
private void write_nPos() M3YC@(N% k
{ 8g6G},Y0
try{ pF7S("#R
output = new DataOutputStream(new FileOutputStream(tmpFile)); E[tEW0ub
output.writeInt(nStartPos.length); J" U!j
for(int i=0;i<nStartPos.length;i++) o_?A^u
{ -bp7X{&
// output.writeLong(nPos); 6mC% zXR5
output.writeLong(fileSplitterFetch.nStartPos); 0]2@T=*kTY
output.writeLong(fileSplitterFetch.nEndPos); *7K)J8kq
} 6Lz:J:Q)
output.close(); e`;U9Z
} Bu#\W
catch(IOException e){e.printStackTrace ();} Mf`@X[-;
catch(Exception e){e.printStackTrace ();} * NdL4c~
} yYvv!w+@Q
g BV66L
7r$'2">K(
//读取保存的下载信息（文件指针位置） S/Gy:GIf
private void read_nPos() leO..M
{ ef]60OtP
try{ 8~vE
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); k[/`G5
int nCount = input.readInt(); v:u=.by99
nStartPos = new long[nCount]; V,>uM >$
nEndPos = new long[nCount]; ,{g B$8z^
for(int i=0;i<nStartPos.length;i++) )k&!&
{ B/bS:
nStartPos = input.readLong(); z+X DN:
nEndPos = input.readLong(); C%;J9(r
} e18}`<tW-
input.close(); 6"|+\
} Fes/8*-
catch(IOException e){e.printStackTrace ();} HsAKz]Mq
catch(Exception e){e.printStackTrace ();} fC!+"g55
} (zhi/>suG
u;=a=>05IR
Xv?'*2J
private void processErrorCode(int nErrorCode) |Whkq/Zg
{ !T1)tGrH
System.err.println("Error Code : " + nErrorCode); !z?;L_Lb
} A9ru]|?
%<;PEQQ|C
_2nNCu (
//停止文件下载 H]&^>Pvh
public void siteStop() ZR@PqS+O/
{ W3Dtt-)E
bStop = true; /PgcW
for(int i=0;i<nStartPos.length;i++) ^:,I #]
fileSplitterFetch.splitterStop(); [h~#5x
T|ZJ$E0
o7t#yw3
} U$AV"F&!&}
} "78BApjWT6
//负责部分文件的抓取 Oo8"s+G
**FileSplitterFetch.java d(;Qe}ok>
*/ S'%!KGVe
package NetFox; R^tDL
hT[w" &3
TW~9<c
import java.io.*; D|X@aUp8}
import java.net.*; /|aD,JVN"
%$}*y
<#No t1R
public class FileSplitterFetch extends Thread { _.K<#S
i2m+s;
xGo,x+U*
String sURL; //File URL {igVuZ(>en
long nStartPos; //File Snippet Start Position Evb %<`gd
long nEndPos; //File Snippet End Position ewp&QH4
int nThreadID; //Thread's ID S$1dXXT
boolean bDownOver = false; //Downing is over 2j*o[kAE
boolean bStop = false; //Stop identical Yp8GW1@
FileAccessI fileAccessI = null; //File Access interface Nk&$b
s.KHm L3
ew\ZFqA;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +oRwXO3W
{ LM?UV)
this.sURL = sURL; SKrkB~%z
this.nStartPos = nStart; wEMg~Hh
this.nEndPos = nEnd; ,5/zTLd
nThreadID = id; mybvD
fileAccessI = new FileAccessI(sName,nStartPos);//定位 j;_ >,\
} ~91) DNaE
XonI
B3-;]6
public void run() DXc3u^ L
{ dMjAG7U
while(nStartPos < nEndPos && !bStop) qo62!q
{ M_EXA _
g=_@j`
J:JkX>n%k=
try{ "I)`gy&
URL url = new URL(sURL); MPF;P&6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =r1@?x
httpConnection.setRequestProperty("User-Agent","NetFox"); .m_-L Y-
String sProperty = "bytes="+nStartPos+"-"; |)IS[:X
httpConnection.setRequestProperty("RANGE",sProperty); [SX>b"L
Utility.log(sProperty); KL6FmL)HH
.Pi8c[
k\`~v$R3
InputStream input = httpConnection.getInputStream(); "L~qsFL
//logResponseHead(httpConnection); sQ>L3F;A`
~(/OB w
S6bW?8`
byte[] b = new byte[1024]; ?Z[`sm
int nRead; wSd o7Lb
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) QocR)aN=+
{ Fi_JF;
nStartPos += fileAccessI.write(b,0,nRead); 2fv`O
//if(nThreadID == 1) IW-lC{hK
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (_'Efpg|
} =&xNdc
#gd`X|<Ch
KG8Km
Utility.log("Thread " + nThreadID + " is over!"); =TG[isC/F9
bDownOver = true; P<{N)H 2r
//nPos = fileAccessI.write (b,0,nRead); pQf5s7
} d1=fA%pJ
catch(Exception e){e.printStackTrace ();} WwBs_OMc
} z~y=(T
} 'k?*?XxG
o9#8q_D9
R@Kzdeo
//打印回应的头信息 2%*mL98WK
public void logResponseHead(HttpURLConnection con) YqSkz|o}m
{ -kI;yL
for(int i=1;;i++) x=~$ik++
{ '#p2v'A
String header=con.getHeaderFieldKey(i); 7lYiufg
if(header!=null) G>yTv`-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >^q7:x\
Utility.log(header+" : "+con.getHeaderField(header)); 0281"aO
else c-gpO|4>
break; POtwT">z
} 6o!Y^^/U
} }:2GD0Ru
rS^+y{7
]E!b&
public void splitterStop() /a:sWmxMT
{ c mI&R(
bStop = true; uF89B-t
} 236,o {9e
8%W(",nd
! >l)*jN8
} V$';B=M
ir/-zp_
MX\v2["FoV
/* zv}3Sl@
**FileAccess.java 3}lT"K
*//文件访问(定位，写) :kz"Wya.
package NetFox; Q"2J2211
import java.io.*; :$J4T;/{
_bm8m4Lk
EmO{lCENk
public class FileAccessI implements Serializable{ @0{vA\
=2rkaBFC
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1?}5.*j<
RandomAccessFile oSavedFile; u|}p3-z|Y
long nPos; x%d\}%]
XFv)]_G
s}5,<|DL
public FileAccessI() throws IOException e0; KmQjG
{ )ir*\<6Y=
this("",0); [@LA<Z_
} N=[# "4I
\2Atm,#4
v@^P4cu;
public FileAccessI(String sName,long nPos) throws IOException ?f\ ~:Gm/
{ "q,.O5q}Y
oSavedFile = new RandomAccessFile(sName,"rw"); y(w&6:
this.nPos = nPos; ;:5Ahfo \
oSavedFile.seek(nPos); O h{>xg
} ]6BV`r]
^;@Q3~DpP%
f;7I{Z\<
public synchronized int write(byte[] b,int nStart,int nLen) NplWF\5y
{ .lt|$["
int n = -1; -mur`tC
try{ B !}/4"
oSavedFile.write(b,nStart,nLen); \p%,g&^ x
n = nLen; ]W9{<+&
} n 9X:s?B/
catch(IOException e) Op2@En|d
{ #5b}"xK{
e.printStackTrace (); 9nrmz>es|-
} td"D&1eQ@
<bbC&O\
)=]u]7p}
return n; -cL{9r&X
} &}q;,"
4[o/p8*/
cU
} c?H@HoF
e#/SFI0m
5_\+8A*
/* @3_[NI%
**SiteInfoBean.java jMV9r-{*+
*/ -Y=o
package NetFox; 94CHxv
#i1z&b#@
yy(.|
public class SiteInfoBean { a2!;$B%
CL)*cu6zG
N" =$S|Gs
private String sSiteURL; //Site's URL 9-( \\$%
private String sFilePath; //Saved File's Path BdQ/kXZu+
private String sFileName; //Saved File's Name }F<=
private int nSplitter; //Count of Splited Downloading File ]aN]Ha
vkgAI<
q0y#Y
public SiteInfoBean() Fk*C8
{//nSplitter的缺省值为5 cq#=Vb
//default value of nSplitter is 5 &]_2tN=S$
this("","","",5); dum(T
} j :$Ruy
4!k0
li7"{+ct
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L7rH=gZ&!]
{ &s>E~M0+J
sSiteURL= sURL; ?Tr\r1s]
sFilePath = sPath; }VDJ
sFileName = sName; (S)jV0
this.nSplitter = nSpiltter; (ibj~g?U,
]r\d 5
T_NN.Ol
} qvN`46c
WLkfo6Nw
`vc?*"
public String getSSiteURL() sb"h:i>O4
{ kmZ U;Z
return sSiteURL; vZJu=t
} I/`\>Hk
*ud/'HR8]
t8_i[Hw6D
public void setSSiteURL(String value) )~LqBh
{ >9i%Yuy](
sSiteURL = value; l/6$BPU`
} t[=teB v<
ul!e!^qwx
FNy-&{P2
public String getSFilePath() S #6:!
{ L[aA4`
return sFilePath; #-{^={p"
} t}x^*I$*
7S.E,\Tws
$s`#&.>c-
public void setSFilePath(String value) ,he1WjL
{ Cak-J~=
sFilePath = value; R^+,D
} FwaYp\z
yD:}&!\}
;9"6g=q
public String getSFileName() Cj1nll8c
{ DR c-L$bD
return sFileName; 5ji#rIAhxh
} sMHP=2##
uz'MUT(68
:vo#(
public void setSFileName(String value) kB3@;z:
{ O&@pi-=o
sFileName = value; ay`A Gr
} .0b4"0~T6
? e<D +
rcU*6`IWA
public int getNSplitter() ''3b[<
{ dk[MT'DV
return nSplitter; aYrbB#
} 6)j/"9oY
qfS ]vc_N
*)xjMTJ%
public void setNSplitter(int nCount) W0;MGBfb
{ (_Ky'.
nSplitter = nCount; e{E8_2d
} I|/\L|vo
} KbM1b
u.9syr
"*JyNwf
/* `Ti?hQm/
**Utility.java uB>OS1=
*/ 6X[Mn2wYW
package NetFox; rGUu K0L&
pZV=Co3!I
MYMg/>f[
public class Utility { mr<camL5
MCO`\"`l
y\@INA^
public Utility() 1T/ 72+R0
{ r"bV{v
4ztU) 1
\Jm^XXgS
} >})W5Y+
z 8y.@<6
//线程睡眠 y41,T&ja
public static void sleep(int nSecond) 5Zy%Nam'gN
{ W+`T:Mgh
try{ $c1xh.
Thread.sleep(nSecond); =.\PG[
} ?*dt JL
catch(Exception e) ck\TTNA
{ `g^bQx
e.printStackTrace (); -APbN(Vi
} :O/QgGZN$
} ;nbbKQ]u
G'0JK+=o
//日志 s~g0VNu Y
public static void log(String sMsg) R@A"U[*
{ [|tlTk
System.err.println(sMsg); #H-EOXy
} kJk6lPSqi7
A?4s+A@Eg
1;"DIsz@d
public static void log(int sMsg) zY2o;-d|4
{ x't@Mc
System.err.println(sMsg); ?AYb@&%
} B'8T+qvA
} |DkK7gw
M&J$9X
'h3yxf}\
/* r O-=):2
**TestMethod.java K_o[m!:jU
*/ u5rHQA0%
package NetFox; :)DvZxHE@
ZIs=%6""&
Apbgm[m|{
public class TestMethod { kj/v$m
iCNJ%AZH
I~)A!vp
public TestMethod() QQ\\:]iM
{ ///xx/weblogic60b2_win.exe k<QZ_*x}G
try{ f?W"^6Df
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5KC Zg'h
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /j"aOLL|
SiteFileFetch fileFetch = new SiteFileFetch(bean); x9i^_3Z
fileFetch.start(); TxvvCV^
} >B$J
catch(Exception e){e.printStackTrace ();} $5N\sdyZxg
s}g3*_"
tf4clzSTa
} o[B"J96b
O~4Q:#^c
*yqke<o9)
public static void main(String[] args) DsCbMs=Y
{ tJ9gwx7Pg
new TestMethod(); ZYs?65.
} <8YIQA
} !P@4dG
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