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)); 3HpqMz
} M7cD!s@'I
for(int i=0;i<nEndPos.length-1;i++) r)pt(*KHo
{ Sb/?<$>
nEndPos = nStartPos[i+1]; Sv{n?BYq
} peO@ZKmM
nEndPos[nEndPos.length-1] = nFileLength; :5,~CtF5 `
} 95z|}16UK
} 1>j,v+
qBX_v5pvVA
'-YiV
//启动子线程 'E3T fM
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1vj@qw3
for(int i=0;i<nStartPos.length;i++) 4d5c]%
{ Sk cK>i.[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X]p3?"7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), OW4j!W
nStartPos,nEndPos,i); qqf`z,u
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X$we\t
fileSplitterFetch.start(); #dUKG8-HJ
} {MUiK5:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,%*UF6B M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); BX0lk
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Op ar+|p\
nEndPos = " + nFileLength); k773h`;
// fileSplitterFetch[nPos.length-1].start(); ES&u*X:
J 7R(X
J&>@>47
//等待子线程结束 6+IhI?lI=
//int count = 0; I]v2-rB&-
//是否结束while循环 P);s0Y|@H
boolean breakWhile = false; DJ,LQj
i *.Y
z_$c_J
while(!bStop) g2|Myz)
{ i"0Bc{cQ
write_nPos(); 5p[}<I{
Utility.sleep(500); QPDh!A3T
breakWhile = true; "kyCY9)%
wS*r<zj
#XDgvX >
for(int i=0;i<nStartPos.length;i++) q>2bkcGY#
{ Z)`)9]*
if(!fileSplitterFetch.bDownOver) o{sv<$
{ xR0T'@q
breakWhile = false; eut2x7Z(c
break; iQgg[ )
} %;k Hnl
} `s CwgY+
if(breakWhile) w+R/>a(]
break; 2F:qaz
}8ubGMr,Y
.d1ff];
//count++; 9;e!r DW,#
//if(count>4) kP ]Up&'
// siteStop(); f$xXR$mjf
} n^4R]9U
2CzhaO
(?|M'gZ
System.err.println("文件下载结束！"); p"ytt|H
} aV'bI
catch(Exception e){e.printStackTrace ();} ;t{q]"? W
} o6[.$C
ApCU|*r)
]$@a.#}
//获得文件长度 xak)YOLRV
public long getFileSize() }L_YpG7
{ xQu|D>kv87
int nFileLength = -1; JI5o~;}m
try{ t@qf/1
URL url = new URL(siteInfoBean.getSSiteURL()); t5-O-AI[b{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]y0Y(
httpConnection.setRequestProperty("User-Agent","NetFox"); }<04\t?
F^u12R)
>NKJ@4Y
int responseCode=httpConnection.getResponseCode(); =8\.fp
if(responseCode>=400) ?R)]D:`
{ P1-eDHYw
processErrorCode(responseCode); bC<W7qf]}
return -2; //-2 represent access is error HT;^u"a~
} ]3_b3@k
,;`f* #
Y,}_LS$f
String sHeader; Jl/wP
=fcg4h5(
KxkBP/`3Q
for(int i=1;;i++) yq%5h[M
{ Za:j;u Y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); gg/`{
//Utility.log(in.readLine()); ?_NKyiu95
sHeader=httpConnection.getHeaderFieldKey(i); h[mT4e3c
if(sHeader!=null) bF"l0 jS
{ R/+$ :
if(sHeader.equals("Content-Length")) v-1}&K
{ &xnQLz:#
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); vF27+/2+R
break; S+T/(-W
} h aAY=:
} vY4sU@+V
else AQ~ xjU
break; N6Mr#A-{
} G*CPj^O
} W7S~~
catch(IOException e){e.printStackTrace ();} FnO@\{M"A
catch(Exception e){e.printStackTrace ();} C-&ymJC|
f<YYo
Q\$3l'W
Utility.log(nFileLength); %2\Hj0JQQ
<3;p>4gN
n Nt28n@
return nFileLength; .IeO+RDQ
} bKQho31a'
2e`}O
jxog8E
//保存下载信息（文件指针位置） 23}` e
private void write_nPos() jf9+H!?^N
{ bv+u7B6,
try{ ){;XI2
output = new DataOutputStream(new FileOutputStream(tmpFile)); QZzamT)"
output.writeInt(nStartPos.length); _ \D%
for(int i=0;i<nStartPos.length;i++) q(KjhM
{ g>lZs
// output.writeLong(nPos); -vvyG
output.writeLong(fileSplitterFetch.nStartPos); @-$8)?`q
output.writeLong(fileSplitterFetch.nEndPos); #<*Vc6pC
} AC,RS7
output.close(); $^]K611w9
} =Hi@q "
catch(IOException e){e.printStackTrace ();} GcBqe=/B!
catch(Exception e){e.printStackTrace ();} Yuvi{ 0
} ]5ZXgz
GK@OdurAR
Su#0F0
//读取保存的下载信息（文件指针位置） !}&|a~U@`k
private void read_nPos() `'YX>u/
{ >i/jqT/
try{ q/i2o[f'n
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); b($hp%+yJ
int nCount = input.readInt(); |+#Zuq
nStartPos = new long[nCount]; Vb0T)C
nEndPos = new long[nCount]; zxyl+tU &
for(int i=0;i<nStartPos.length;i++) :`bC3Mr
{ XM$~HG
nStartPos = input.readLong(); gmGK3am
nEndPos = input.readLong(); $Z]&3VxxY
} :{7+[LcH7
input.close(); Xg)8}
} ">H*InF
catch(IOException e){e.printStackTrace ();} {9x_E {
catch(Exception e){e.printStackTrace ();} o<G 9t6~
} }9fa]D-a?
jI-a+LnEm
?.~1%l!
private void processErrorCode(int nErrorCode) 7N$2N!I(
{ \-\>JPO~<
System.err.println("Error Code : " + nErrorCode); Ew8@{X y
} I ]m
y'R}
nS+Rbhs
//停止文件下载 <:S qMf
public void siteStop() $RD~,<oEm
{ ?cV,lak
bStop = true; /$~1e7W
for(int i=0;i<nStartPos.length;i++) qmrT dG
fileSplitterFetch.splitterStop(); WTSh#L
yaUtDC.|
1NZ"\9=U
} F y+NJSG
} z0 "DbZ;d
//负责部分文件的抓取 >*-%:ub
**FileSplitterFetch.java :j\7</uu
*/ &jqaW2
package NetFox; gQnr.
3jx%]S^z|
pKSCC"i&j
import java.io.*; u?^V4 +V
import java.net.*; oRV}Nz7hr
({uW-%
]Ry9{:
public class FileSplitterFetch extends Thread { }[p{%:tP
PgBEe @.
{:X'9NEE
String sURL; //File URL vX+oZj
long nStartPos; //File Snippet Start Position ^FVdA1~/
long nEndPos; //File Snippet End Position i)i>Ulj*i
int nThreadID; //Thread's ID opcanl9pSW
boolean bDownOver = false; //Downing is over Hm-#Mpw
boolean bStop = false; //Stop identical '/\
FileAccessI fileAccessI = null; //File Access interface `+H=3`}X
}lZEdF9GhG
GBJLB
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException cO?*(e1m=
{ QPlU+5Cx
this.sURL = sURL; i<QDV W9
this.nStartPos = nStart; `4"8@>D
this.nEndPos = nEnd; W}(A8g#6
nThreadID = id; ]S2rqKB
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )2f#@0SVL
} u6|C3,!z"
oF%m
)GP;KUVae
public void run() \/ bd
{ J Enjc/
while(nStartPos < nEndPos && !bStop) %cF`x_h[j
{ ~D52b1f
P\U<,f
qt8Y3:=8l
try{ OSu&vFKz
URL url = new URL(sURL); >M<3!?fW)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <8r"QJY/
httpConnection.setRequestProperty("User-Agent","NetFox"); 8Pn
String sProperty = "bytes="+nStartPos+"-"; +B?qx Q
httpConnection.setRequestProperty("RANGE",sProperty); is.t,&H4P]
Utility.log(sProperty); =EJ&=t
I%T+H[,
pbMANZU[
InputStream input = httpConnection.getInputStream(); iOfm:DTPr
//logResponseHead(httpConnection); l}nVWuD
}x'*3zI
6)INr,d
byte[] b = new byte[1024]; AL]gK)R
int nRead; l+ }=D@l
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) f:;-ZkIU ?
{ N_Us6X
nStartPos += fileAccessI.write(b,0,nRead); G]lGoa}]`u
//if(nThreadID == 1) &PMQ]B
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [gWeD
} :jiEn y
kWzp*<lWe
~ 'ZwD/!e
Utility.log("Thread " + nThreadID + " is over!"); dSDZMB sd
bDownOver = true; *|rdR2R!
//nPos = fileAccessI.write (b,0,nRead); .UK0bxoa
} 2BccE
catch(Exception e){e.printStackTrace ();} WK%cbFq(
} XYcZ;Z9:
} I9?\Jbqg
+Mj6.X
;lMvxt:
//打印回应的头信息 @-@Coy 4Tt
public void logResponseHead(HttpURLConnection con) t3L>@NWG
{ /~LE1^1&U
for(int i=1;;i++) ,np=m17
{ P\"kr?jZP
String header=con.getHeaderFieldKey(i); T?3Q<[SmI
if(header!=null) {&1L &f<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); cy%M$O|hX5
Utility.log(header+" : "+con.getHeaderField(header)); _}[ Du/c
else }?[];FB
break; gM96RY
} ]E9iaq6Z
} (-C)A-Uo&
e@3SF
( 5LCy?-6
public void splitterStop() C[FHqo9M?H
{ Ym'h vK
bStop = true; 8h] TI_
} f&-`+V}U
1]xmOx[mb
n_kwtWX(
} d1~#@6CIz
.@H:P
pGie!2T E
/* '54\!yQ<{
**FileAccess.java /-M:6
*//文件访问(定位，写) @pH2"k| @
package NetFox; #`Su3~T=S
import java.io.*; eWH0zswG
~WA@YjQ]
:Xw|v2z%3
public class FileAccessI implements Serializable{ QK_5gD`$a,
VEps|d3,,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |\(uO|)ju
RandomAccessFile oSavedFile; a`wjZ"}'[
long nPos; [ycX)iM
|/,SNE
"uH>S+%|b
public FileAccessI() throws IOException 0i~U(qoI
{ l7QxngWw
this("",0); I%d=c0>%
} -y.cy'$f
>LBA0ynh {
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public FileAccessI(String sName,long nPos) throws IOException S,5ok0R
{ t$BjJ -G
oSavedFile = new RandomAccessFile(sName,"rw"); x?AG*' h&
this.nPos = nPos; yY VR]HH
oSavedFile.seek(nPos); p]aEC+q
} J3yK^@&&
f:-)S8OJ
sH6;__e
public synchronized int write(byte[] b,int nStart,int nLen) (.-4Jn
{ -XYvjW,|
int n = -1; D07M!U
try{ hQ#e;1uD
oSavedFile.write(b,nStart,nLen); l>6tEOXt
n = nLen; #*h\U]=VS
} Vb,VN?l
catch(IOException e) %a/3*vz/I%
{ SaPE 1^}
e.printStackTrace (); SVU>q:ab
} joY7Vk!<o
k9k39`t
xs= ~N
return n; 7I3_$uF
} CX]1I|T5
rXB;#ypO
9=>q0D2
} :^7w
ZvRa"j
JxIJxhA>
/* W9SU1{*9
**SiteInfoBean.java (?e%w}
*/ Ph3;;,v '
package NetFox; +O/b[O'0
2^r~->
5FOMh"!z\
public class SiteInfoBean { bZxN]6_
o[>d"Kp
-6[DQB
private String sSiteURL; //Site's URL v,<14w
private String sFilePath; //Saved File's Path R"W}\0k
private String sFileName; //Saved File's Name Lt*P&
private int nSplitter; //Count of Splited Downloading File G9:XEEN
=WTSaC
2U)n^
public SiteInfoBean() !q\8`ss
{//nSplitter的缺省值为5 d:)#-x*h7
//default value of nSplitter is 5 fJS:46
this("","","",5); =x<N+vjXY
} dlYpbw}W&<
fo ~uI(rk
wm~7`&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |62` {+
{ =RB {.%
sSiteURL= sURL; n&[CTOV
sFilePath = sPath; vPDw22L;'
sFileName = sName; Fi``l)Tt
this.nSplitter = nSpiltter; P%2v(
qFmw9\Fn
)]@h}K}
} Im;%.J
;e?M;-
?[JP[ qS
public String getSSiteURL() J*;RL`
{ 8?Zhh.
return sSiteURL; ]PS`"o,pF$
} 9@|52dz%
5%jhVys23
.!3e$mhV
public void setSSiteURL(String value) zsp%Cz7T
{ %7ngAIg
sSiteURL = value; hTDK[4e
} {s8c@-'
w;lpJB\
/h>g-zb
public String getSFilePath() z:\9t[e4
{ p@jw)xI
return sFilePath; i.mv`u Dm
} re*}a)iL
=Dn<DV
!Se0&Ob
public void setSFilePath(String value) %#2$B+
{ 03~ ADj
sFilePath = value; I!hh_
} l5D)UO
5f*_K6,v
D40 vCax^J
public String getSFileName() 3"x_Y
{ _ $a3lR
return sFileName; iVFOOsJ@
} Cx TAd[az
R,3cJ Y_%
1GYZ1iA
public void setSFileName(String value) Yc7YNC.
{ G'JHimP2j
sFileName = value; {w2] Is2F
} HPphTu}`
|^Iox0A
WZ'Z"'
public int getNSplitter() 1Dr&BXvf]8
{ 7(84j5zb
return nSplitter; W\l&wR
} YYQvt
F{x+1hct0
sa'1hX^@
public void setNSplitter(int nCount) /"X_{3dq?
{ IAO5li3
nSplitter = nCount; 5_(\Cd<#
} `vBBJ@f4)
} Wj.t4XG!
QXb2jWz
L"b&O<No
/* Bt<)1_
**Utility.java S)U*1t7[
*/ ^+yz}YFM
package NetFox; c5^HGIe1
$9G& wH>{
PMAz[w,R~
public class Utility { s[8. l35|
Y:DopKRD
JvO1tA]ij
public Utility() :SaZhY
{ z"4 q%DC
5Cdn j
]o'o v
} &GLDoLk6[
MG=E 6:
//线程睡眠 ,-6Oma -
public static void sleep(int nSecond) :|bL2T@>[
{ vm@V5oH
try{ ) ^En
Thread.sleep(nSecond); rD}g9?ut
} p)SW(pS
catch(Exception e) mOJdx-q?r
{ BeUyt
e.printStackTrace (); ] hT\"5&6
} }#m9Q[
} vaeQ}F
-@XSDfy7S
//日志 pN^g.
public static void log(String sMsg) #aX#gh}1
{ HR-'8?)R.A
System.err.println(sMsg); nL?P/ \
} Z=&|__+d
[KA^+n
sTd@/>S?p
public static void log(int sMsg) t~L4wr{B
{ J_7w_T/
System.err.println(sMsg); TJv .T2|
} :of([e|u6
} @1oX&#
Z#}sK5s
%UI^+:C
/* j/aJDE(+
**TestMethod.java kEh\@x[
*/ 4ior
package NetFox; ovp/DM
M+:5gMB'
ddgDq0N1j
public class TestMethod { !SK`!/7c?
at?I @By
I7_lKr3
public TestMethod() 48-j
{ ///xx/weblogic60b2_win.exe ;Ci:d*
try{ 76D$Nm
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); L"jA#ULg
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); qIJc\,'
SiteFileFetch fileFetch = new SiteFileFetch(bean); B=OzP+
fileFetch.start(); !\#Wq{p>W*
} DCp8rvUI
catch(Exception e){e.printStackTrace ();} P6_Hz!vE
V< F&\
I3>8B
} N'y<<tTA
+2{ f>KZ
rfonM~3?'
public static void main(String[] args) f:M^q ;
{ '=;e# C`<{
new TestMethod(); F`4W5~`
} x:-NTW -g
} :Fhk$?/r
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