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)); 2F%2K?$`Ej
} }F!tM"X\
for(int i=0;i<nEndPos.length-1;i++) *|{1`{8n
{ h6Ovl
nEndPos = nStartPos[i+1]; }`ox;Q
} Z@2^> eC
nEndPos[nEndPos.length-1] = nFileLength; Xia4I* *
} R.@I}>
} wW EnAW~
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Q"7vzri
//启动子线程 Rsd~t_a1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |(u6xPs;P
for(int i=0;i<nStartPos.length;i++) <|8N\FU{
{ 1Bp?HyCR
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), td JA?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *eL&fC
nStartPos,nEndPos,i); @rI+.X
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "A\h+q-
fileSplitterFetch.start(); @( p9}
} 5, "
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6l]jmj)/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +-~8t^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1[p6v4qO{
nEndPos = " + nFileLength); Nk?eVJ)
// fileSplitterFetch[nPos.length-1].start(); 0Lb:N]5m8
o|(Ivt7jk
Vl'Gi44)3"
//等待子线程结束 H c,e&R
//int count = 0; w_qX~d/
//是否结束while循环 V1di#i:
boolean breakWhile = false; o-i9 :AHs
AK$&'t+$}7
*ThP->&:(
while(!bStop) 4FQB%3>*
{ @=rYOQj|
write_nPos(); NW_i<#
Utility.sleep(500); 0RFBun{
breakWhile = true; $-Iui0h
n=Ze p{^
JOwm|%>3a
for(int i=0;i<nStartPos.length;i++) D[/h7Ha
{ X'FDQoH
if(!fileSplitterFetch.bDownOver) C- 5QhD
{ !=Scpo_
breakWhile = false; Qe4O N3X!
break; wtM1gYl^
} 3qf?n5"8
} 41uiW,
if(breakWhile) #mKF)W
break; sbv2*fno5
OFe-e(c1
p{|!LcSU$2
//count++; W_.WMbT
//if(count>4) %9vl
// siteStop(); DwmK?5p
} sg`
hZ_@U?^
VOJA}$
System.err.println("文件下载结束！"); cYmgJBG
} #{_iNra9
catch(Exception e){e.printStackTrace ();} (vP<}
} 2$r8^}Nj?
}TQa<;Q
|P0!dt7sQ
//获得文件长度 n f.H0i;
public long getFileSize() ,>+B>lbJ*
{ BTc }Kfae
int nFileLength = -1; 9*Q6/?v
try{ 9$k0
URL url = new URL(siteInfoBean.getSSiteURL()); )_n=it$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &cGa~#-u
httpConnection.setRequestProperty("User-Agent","NetFox"); ?}RPnf
+>3jMs~&
t =V| '
int responseCode=httpConnection.getResponseCode(); 3c%_RI.
if(responseCode>=400) unKPqc%q=n
{ e&nE
processErrorCode(responseCode); f+!k:}K
return -2; //-2 represent access is error )Fgu'
} &&% oazR=
k,eo+qH.Hz
}ChScY
String sHeader; ~+ kfb^<-
3iM7c.f*/
j)ME%17
for(int i=1;;i++) JR_%v=n~x
{ !mZDukfjQ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); UpaF>,kM
//Utility.log(in.readLine()); QUeuN?3X\
sHeader=httpConnection.getHeaderFieldKey(i); .af+h<RG4$
if(sHeader!=null) ZyM7)!+kPa
{ r=-b@U.fk>
if(sHeader.equals("Content-Length")) Ptm=c6H('
{ iD*21c<kd
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .(RZ&*4
break; xv"v='
} dBw7l}
} |yl,7m/B-G
else a[Nm< qV05
break; nz|6CP
} 3n,jrX75u
} FI,K 0sO/|
catch(IOException e){e.printStackTrace ();} jB<B_"
catch(Exception e){e.printStackTrace ();} oN2#Jh%dH
xkCM*5:
/!?b&N/d)
Utility.log(nFileLength); EHy15RL
D V\7KKJE
qjObu\r
return nFileLength; ~R&rQJJeJ
} qj9[mBkP"
U&i#cF
{]bmecz
//保存下载信息（文件指针位置） Y'{}L@"t
private void write_nPos() tD*k
{ !2kM
try{ %QG3~b% h
output = new DataOutputStream(new FileOutputStream(tmpFile)); uK]-m
output.writeInt(nStartPos.length); k%3)J"|/
for(int i=0;i<nStartPos.length;i++) IL go:xQ
{ <6Y|vEo!N
// output.writeLong(nPos); _\=x A6!
output.writeLong(fileSplitterFetch.nStartPos); )DmydyQ'
output.writeLong(fileSplitterFetch.nEndPos); CBO*2?]s
} B}S+/V` Y5
output.close(); o}DRp4;Ka
} _dELVs7OL
catch(IOException e){e.printStackTrace ();} qfG:vTm
catch(Exception e){e.printStackTrace ();} Nw9@E R
} E[WU
#.rkvoB0N
R?zlZS.~
//读取保存的下载信息（文件指针位置） idB1%?<
private void read_nPos() eL>wKu:r
{ -:95ypi
try{ j!@T@ 8J
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~/X8Hy!-
int nCount = input.readInt(); Fv7]1EO.
nStartPos = new long[nCount]; t{g@z3
nEndPos = new long[nCount]; ^KdT,^6T
for(int i=0;i<nStartPos.length;i++) &\I<j\F2/
{ R%4Yg(-Q
nStartPos = input.readLong(); [(2^oTSRaq
nEndPos = input.readLong(); fP:]s@$
} dG7d}0Ou'
input.close(); 2 431v@
} qdLzB
catch(IOException e){e.printStackTrace ();} RP$h;0EQG
catch(Exception e){e.printStackTrace ();} %%|pJ%}Q>
} >yr;Y4y7K
4qQE9fxdY
"b402"&
private void processErrorCode(int nErrorCode) /Yb8= eM
{ tmOy"mq67
System.err.println("Error Code : " + nErrorCode); *xJ]e.
} `v@Z|rv,
gyq6LRb
CuK>1_Dq
//停止文件下载 Fm=jgt3wv8
public void siteStop() cHt4L]n8n
{ kQe<a1 8
bStop = true; ]h~F%
for(int i=0;i<nStartPos.length;i++) i9Beap/t$
fileSplitterFetch.splitterStop(); 0J^Z)U>j
H#7=s{u
*Lxt{z`9
} '%4fQ%ID}
} W**[:n+
//负责部分文件的抓取 *+zFsu4l
**FileSplitterFetch.java =dH=3iCG
*/ SHs [te[
package NetFox; V,=5}qozQ
XlD=<$Nk7
iZ>P>x\
import java.io.*; p6NPWaBR
import java.net.*; _h4]gZ
!?_CIt$p
akk*f+TD`
public class FileSplitterFetch extends Thread { FAL#p$y}
ZB|s/
B8eZ}9X
String sURL; //File URL qE3Ud:j
long nStartPos; //File Snippet Start Position C[<{>fl)
long nEndPos; //File Snippet End Position 'zav%}b]L
int nThreadID; //Thread's ID +'SL5d*
boolean bDownOver = false; //Downing is over Y-Q)sv
boolean bStop = false; //Stop identical [u;(4sa}
FileAccessI fileAccessI = null; //File Access interface H>D sAHS
Y@:l!4DI
_f8H%Kgk;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException MM]0}65KG
{ t\LE\[XM>
this.sURL = sURL; 50dN~(;p
this.nStartPos = nStart; )b (+=
this.nEndPos = nEnd; 5L<A7^j
nThreadID = id; Xp|4WM
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8\9W:D@"x
} b:'8_jL
u$[&'D6
lAA&#-#YG
public void run() bDIhI}P
{ yUf`L=C:
while(nStartPos < nEndPos && !bStop) b$0;fEvIJn
{ ?]bx]Y;
ZbVn"he
% >a /m.$
try{ y`8U0TE3R
URL url = new URL(sURL); Ym"^Ds}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]hy@5Jyh
httpConnection.setRequestProperty("User-Agent","NetFox"); Du +_dr^4
String sProperty = "bytes="+nStartPos+"-"; QHja4/
httpConnection.setRequestProperty("RANGE",sProperty); WF*j^ %5
Utility.log(sProperty); xjF>AAM_Px
~:k r;n2
)7!,_r
InputStream input = httpConnection.getInputStream(); TghT{h@
//logResponseHead(httpConnection); <$hv{a
4YI6&
E+EcXf
byte[] b = new byte[1024]; Ek_&E7
int nRead; )MSCyPp5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) k&:q|[N
{ @aN~97 H\
nStartPos += fileAccessI.write(b,0,nRead); k"%JyO8Y
//if(nThreadID == 1) %).I&)i
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); AX&Emz-
} GIkeZV{4}
<,it<$f#
>Ik%_:CC`
Utility.log("Thread " + nThreadID + " is over!"); _-H,S)kI`
bDownOver = true; ?Fl O,|
//nPos = fileAccessI.write (b,0,nRead); 7p\&D?
} U[Sh){4j
catch(Exception e){e.printStackTrace ();} <+r~?X_
} p5OoDo
} `Ix`/k}
!5h-$;
'AWWdz
//打印回应的头信息 i;/;zG^=_
public void logResponseHead(HttpURLConnection con) }eA)m
{ =O"l/\c^
for(int i=1;;i++) Drf Au
{ #@w/S:KbJt
String header=con.getHeaderFieldKey(i); pYm#iz
if(header!=null) 7O%^4D
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ooB9iNo^
Utility.log(header+" : "+con.getHeaderField(header)); =`>ei
else 6:8Nz
break; >'=9sCi
} >EA\KrjW
} tUZfQ
G9xO>Xp^Al
ZwY mR=
public void splitterStop() yK9EHJ$
{ E_$nsM8?
bStop = true; ,Xn%0]
} p ^TCr<=
^~TE$i<
ar 7.O;e
} _qk&W_u
\(=xc2
G\5Bdo1g
/* of7p~{3H
**FileAccess.java 6&6dd_K(
*//文件访问(定位，写) {|OXiRm'
package NetFox; S76MY&Vx23
import java.io.*; -qvMMit%7
g,o46`6"
%jf|efxo
public class FileAccessI implements Serializable{ 7rbw_m`12-
'byTM?Sp{
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 (RrC<5"
RandomAccessFile oSavedFile; -OmpUv-O"
long nPos; !B#lZjW#
;.xKVH/@
{*g{9`
public FileAccessI() throws IOException F4"bMN
{ d:vc)]M>f{
this("",0); xL<c/B`-:
} ^?\|2H
9An\uH)mL
?li/mc.XG
public FileAccessI(String sName,long nPos) throws IOException Sfc,F8$&N
{ H/Ql
oSavedFile = new RandomAccessFile(sName,"rw"); Y%y
this.nPos = nPos; B<Cg_C
oSavedFile.seek(nPos); 2'OY,Ooe
} @qW$un:
7I]?:%8h
x./"SQ=R+
public synchronized int write(byte[] b,int nStart,int nLen) l O*
{ /B 3\e3
int n = -1; l_9ZzN
try{ &Qj1uf92.
oSavedFile.write(b,nStart,nLen); 9C Ki$L
n = nLen; ~@QAa (P.
} "|Yy"iB[
catch(IOException e) sredL#]BA
{ |/8!PKm
e.printStackTrace (); MT)q?NcG
} ^r(]S%
8KkN "4'
PA*k|
return n; ?UIW&*h}
} Z5P4 H
=TzJgx
{(asy}a9K
} #j+cl'
.!lLj1?p
,!,M'<?"
/* =oiz@Q@H
**SiteInfoBean.java o$U{.#
*/ qe e_wx
package NetFox; cH:&S=>h
iPG:w+G
'L9hM.+
public class SiteInfoBean { +eKLwM
#4"eQ*.*"
Sd.Km a
private String sSiteURL; //Site's URL (~5]1S}F
private String sFilePath; //Saved File's Path /F|VYl^_
private String sFileName; //Saved File's Name Slv:CM M
private int nSplitter; //Count of Splited Downloading File `)KGajB
MF*4E9Ue.
L\bcR
public SiteInfoBean() kSCpr0c
{//nSplitter的缺省值为5 &%)F5PT
//default value of nSplitter is 5 XN?my@_HpM
this("","","",5); :P%?!'M
} mMWhUr
rFm?Bu
c(b`eUOO
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Bf+~&I#E
{ 6CGk*s
sSiteURL= sURL; 3fZoF`<a
sFilePath = sPath; S5Pn6'w
sFileName = sName; y@2"[fo3~
this.nSplitter = nSpiltter; %1{O
~ oq.yn/1
hBaG*J{
} {-]K!tWda
;p<BiC$b
iyUnxqP
public String getSSiteURL() ,+C?UW
{ (G$Q\>
return sSiteURL; =,qY\@fq
} iYw1{U
O*]}0*CT
q;f L@L@-
public void setSSiteURL(String value) 'gD./|Z0
{ /|h+,]< >
sSiteURL = value; YD9vWk\/
} u$ci{<
=JPY{'VO
on5\rY<I:@
public String getSFilePath() 1~2+w]-kU
{ P%vouC0W
return sFilePath; Q?([#
} R*k;4*1u
a0B%x!y^
"fSaM&@[B
public void setSFilePath(String value) U;u4ey
{ (6[/7e)
sFilePath = value; OS>%pgv
} #hu`X6s"
83#<Yxk~
| "M1+(k7
public String getSFileName() Ytqx0
{ Hl{ul'o
return sFileName; g_>E5z.
} n? =O@yq
cf"!U+x
,Tx38
public void setSFileName(String value) ~-%z:Re'_
{ ZdPqU\G^q
sFileName = value; _ogN
} %X%f0J
\FCPD.2s+
i/!KUbt
public int getNSplitter() WHLTJ]OB
{ d#ab"&$bv
return nSplitter; "Z&_*F.[O
} P+_1*lOG
"^ dMCS@
^AZv4H*~
public void setNSplitter(int nCount) P-yVc2YH
{ C+t|fSJ
nSplitter = nCount; d}Y#l}!E6
} sE{5&aCSR
} n3eWqwQ$5
E\9HZ;}G
5UK}AkEe&x
/* N693eN!
**Utility.java +~ Y.m8
*/ 5s4x%L (~}
package NetFox; .;,,{;
v9f%IE4fX
XGYsTquSe
public class Utility { !g|[A7<|
h{jm
o{hZjn-
public Utility() 3(*vZ
{ i_`Po%
zt!>
Zba<|C
} LCHw.
Pe11azJ
//线程睡眠 ]]_c3LJ2`
public static void sleep(int nSecond) dww4o~hO
{ FS!vnl8`
try{ or7l}X
Thread.sleep(nSecond); *8u<?~9F
} a%an={
catch(Exception e) 5~#oQ&
{ w-@6qMJ
e.printStackTrace (); ye}86{l
} Aaz:C5dtU
} G#E8xA"{/
IkGM~3e
//日志 0/%RrE
public static void log(String sMsg) U`)d `4"
{ tpgD{BY^wJ
System.err.println(sMsg); b`;&o^7gMO
} g]?>6 %#rA
u:wf:^
<<@F{B7h
public static void log(int sMsg) /7.//klN
{ +*eVi3
System.err.println(sMsg); <0Gk:NB,
} -xyY6bxL
} ybIqn0&[
iUqD>OV
jG#e%`'
/* gS|6,A9
**TestMethod.java rTST_$"_6
*/ %hz5)
package NetFox; Y%(8'Ch
Q5 o0!w
YCdtf7P=q
public class TestMethod { Y|KT3
Cw5B p9
nLrCy5R:
public TestMethod() @j(2tJ,w
{ ///xx/weblogic60b2_win.exe srKEtd"
try{ a:1$idj
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {aU|BdATI
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {817Svp@
SiteFileFetch fileFetch = new SiteFileFetch(bean); A9GSeW<
fileFetch.start(); :j32 :/u
} QUz4 Kt
catch(Exception e){e.printStackTrace ();} .rlLt5b%
a`U/|[JM
_@_EQ!=
} X LY>}r
4i"fHVp8
IfP?+yPa
public static void main(String[] args) G//hZwf0
{ lxR]Bh+
new TestMethod(); @)ls+}=Y
} _]0<G8|Rv
} YlZ&4
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