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)); cJ8F#t
} vo`wYJ3W
for(int i=0;i<nEndPos.length-1;i++) fsjA7)/
{ $hSu~}g
nEndPos = nStartPos[i+1]; *-|+phim
} ]QT0sGl
nEndPos[nEndPos.length-1] = nFileLength; ;*W]]4fy
} sp**Sg)
} g@Ni!U"_c
/"CKVQ
HxY,R^
//启动子线程 BQS9q'u_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; .4!N#'
for(int i=0;i<nStartPos.length;i++) F`I-G~e
{ sjTsaM;<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $xu?zd"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;wQWt_OtuJ
nStartPos,nEndPos,i); F41!Dj7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P1) 80<t
fileSplitterFetch.start(); `FJnR~d
} 29sgi"
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0!vC0T[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); xk|$Oa
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \;7DS:d@
nEndPos = " + nFileLength); FOk @W&
// fileSplitterFetch[nPos.length-1].start(); NxXVW
jq0tMTb%L
50DPzn
//等待子线程结束 NNl/'ge<\
//int count = 0; M@'V4oUz
//是否结束while循环 (C-z8R Z6
boolean breakWhile = false; WQ5sC[&
&YT7>z,
Bd NuhV`0
while(!bStop) '-i tn
{ =|U2 }U;
write_nPos(); 4G>|It
Utility.sleep(500); _kY5 6
breakWhile = true; zi?'3T%Ie
^CK)q2K>[
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for(int i=0;i<nStartPos.length;i++) ax^${s|{-
{ 6ZG)`u".("
if(!fileSplitterFetch.bDownOver) T![K i
{ HJJ^pk&
breakWhile = false; xu:m~8%
break; F7;xf{n<
} {-Y_8@&
} kuH;AMdv
if(breakWhile) g?>AY2f[5
break; VNYLps@4H
<Y#R]gf1
!GIsmqVY
//count++; j&Hn`G
//if(count>4) *(vq-IE\$
// siteStop(); -YuvEm#f
} sRZ:9de+
zDl, bLiJ
O h"^
System.err.println("文件下载结束！"); i9xv`Ev=R
} W1@;94Sb~
catch(Exception e){e.printStackTrace ();} AltE~D/4
} wFJK!9KA8
%UQ{'JW?K
,oG"wgf
//获得文件长度 aydal9M
public long getFileSize() r6$=|Yto
{ 0wkLM-lN
int nFileLength = -1; eYcx+BJ
try{ k_a'a)`$6
URL url = new URL(siteInfoBean.getSSiteURL()); ob00(?;H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .u*].As=
httpConnection.setRequestProperty("User-Agent","NetFox"); 'u3+k.
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=+"'=o
int responseCode=httpConnection.getResponseCode(); <=inogf
if(responseCode>=400) o 4b{>x
{ KB"iF}\P0
processErrorCode(responseCode); r{Q< a
return -2; //-2 represent access is error V^{!d}
} ZWa#}VS}-n
OV/FQH;V
yhdG 93
String sHeader; bvgD;:Aj
O2,g]t~C
W<LaR,7
for(int i=1;;i++) 5qr!OEF2
{ vf yva
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); fv_wK_. %:
//Utility.log(in.readLine()); GiZ'IDV
sHeader=httpConnection.getHeaderFieldKey(i); 84!4Vz^
if(sHeader!=null) SNU bY6
{ rl^LSz
if(sHeader.equals("Content-Length")) -7O/ed+
{ h(8;7}K
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); o3yqG#dA
break; cx,A.Lc
} +lT]s#Fif
} PbPP1G')
else ]= NYvv>H
break; :'dc=C
} 1QJ$yr
} f`,Hr?H
catch(IOException e){e.printStackTrace ();} .O#lab`:2
catch(Exception e){e.printStackTrace ();} 'U"3'jh
Gx!RaZ1
NACY;XQ%
Utility.log(nFileLength); k@aP&Z~
8@aS9th$
#5C3S3e=
return nFileLength; O|RO j
} W`'|&7~
#(IMRdUf
)M N yOj
//保存下载信息（文件指针位置） tKeO+6l
private void write_nPos() XC1lo4|
{ erP>P
try{ 9,5II0N L
output = new DataOutputStream(new FileOutputStream(tmpFile)); 62x< rph
output.writeInt(nStartPos.length); &&]!+fTZ\(
for(int i=0;i<nStartPos.length;i++) vEe
{ ++!E9GU{
// output.writeLong(nPos); 'TrrOq4
output.writeLong(fileSplitterFetch.nStartPos); i`aG
output.writeLong(fileSplitterFetch.nEndPos); YB{E=\~
} #=H}6!18
output.close(); JX)z<Dz$
} Cj1UD;
catch(IOException e){e.printStackTrace ();} ,:(leWeA9
catch(Exception e){e.printStackTrace ();} *wB-lg7%
} NoAb}1uae
MJ9SsC1
uHro%UAd
//读取保存的下载信息（文件指针位置） ^X;Xti
private void read_nPos() ;]M67ma7C
{ 'D"K`Vw
try{ 1ysLZ;K
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]XGn2U\
int nCount = input.readInt(); 9BD|uU;0
nStartPos = new long[nCount]; m90R8 V
nEndPos = new long[nCount]; .XKvk(9
for(int i=0;i<nStartPos.length;i++) PBs<8xBx^
{ g**%J Xo
nStartPos = input.readLong(); *z"1MU
nEndPos = input.readLong(); OEE{JVeI
} =P;;&j3Z
input.close(); iB3+KR
} f5b`gvCY,#
catch(IOException e){e.printStackTrace ();} pd>a6 lI`
catch(Exception e){e.printStackTrace ();} ~R@m!'Ik
} !$xEX,vj|W
N^yO- xk
KHus/M&0
private void processErrorCode(int nErrorCode) h!N&gZ[0
{ y]YS2^
System.err.println("Error Code : " + nErrorCode); wt.{Fqm
} Mr NOcx&
e3={$Ah
O?,i?
//停止文件下载 ) .-(-6=R
public void siteStop() 3:8nwt
{ 4EhBpTg
bStop = true; :$cSQ(q9a
for(int i=0;i<nStartPos.length;i++) a H|OA\<
fileSplitterFetch.splitterStop(); K@sP~('
_{`'{u
]AC!R{H
} u1|P'>;lF
} )~blx+\y
//负责部分文件的抓取 'Tf#S@o
**FileSplitterFetch.java 30(m-D$K>9
*/ r{!"%03H_
package NetFox; uU ?37V
9poEUjBI
wz0$g4
import java.io.*; ?tC}M;~
import java.net.*; g.Caapy
B mBzOk^
/yw\(|T
public class FileSplitterFetch extends Thread { 8@W/43K8-
9 /Ai(
C|d!'"p
String sURL; //File URL !:5`im;i
long nStartPos; //File Snippet Start Position K?Xo3W%K
long nEndPos; //File Snippet End Position 0o=6A<#x
int nThreadID; //Thread's ID K]pKe"M
boolean bDownOver = false; //Downing is over y|+~>'^JR
boolean bStop = false; //Stop identical p]V-<
FileAccessI fileAccessI = null; //File Access interface R#7+
^Q)gsJY|I
-90ZI1O`
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /Xu;/MMpd3
{ Z:o 86~su
this.sURL = sURL; TCKI
this.nStartPos = nStart; 2.Eu+*UC
this.nEndPos = nEnd; >.O*gv/_
nThreadID = id; A D}}>v
fileAccessI = new FileAccessI(sName,nStartPos);//定位 22Y!u00D
} %j[LRY/
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public void run() Bsu=^z
{ ! F;<xgw
while(nStartPos < nEndPos && !bStop) D=82$$
{ RdvPsv}D
D#/%*|
Wq{d8|)1
try{ X6Nm!od'
URL url = new URL(sURL); 5<)gCHa
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 43u PH1 )
httpConnection.setRequestProperty("User-Agent","NetFox"); kHJDX;
String sProperty = "bytes="+nStartPos+"-"; PK2Rj%
httpConnection.setRequestProperty("RANGE",sProperty); wKi}@|0[@
Utility.log(sProperty); }KD7 Y
}[KDE{,V
6& &}P79
InputStream input = httpConnection.getInputStream(); A1|7(Sow
//logResponseHead(httpConnection); A^4kYOe
EBIa%,
~D-JZx
byte[] b = new byte[1024]; RvPniT(<?
int nRead; PV]k3&y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) w`.T/
{ y=oVUsG
nStartPos += fileAccessI.write(b,0,nRead); (N*<\6kr
//if(nThreadID == 1) l6S19Kv
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *< $c =
} re ]Ste
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u8<&F`7j
Utility.log("Thread " + nThreadID + " is over!"); GTp?)nh^
bDownOver = true; ^EC)~HP@C
//nPos = fileAccessI.write (b,0,nRead); co$Hi9JE
} z|G|Y 22
catch(Exception e){e.printStackTrace ();} jHu,u|e0>S
} ,#P,B;r~
} &Hlm{FHU
7z/(V\9B
+(=0CA0GE
//打印回应的头信息 +3/k/W
public void logResponseHead(HttpURLConnection con) *w'q
{ Q3NPwM
for(int i=1;;i++) DnG/ n
{ &O+sK4P
String header=con.getHeaderFieldKey(i); ;T5,T
if(header!=null) b"R, p=M
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,c,Xd
Utility.log(header+" : "+con.getHeaderField(header)); l50|` 6t
else 08Pt(kzNA
break; ,Lt~u_lve
} RjR&D?dc
} C@TN5?Z
{[M0y*^64$
[)Z'N/;0
public void splitterStop() '!j #X_;
{ C=oM,[ESQ0
bStop = true; ?qd,>
} i\kTm?BQZ
F,p`-m[q
DEUd[
} wMH[QYb<*
Ss@u,`pr
Xmap9x
/* ] ?DDCew
**FileAccess.java Q(~3pt
*//文件访问(定位，写) @9}),hl`
package NetFox; "*Lj8C3|n
import java.io.*; 8 3z'#
:X'*8,]KHH
E;6Y? vJ
public class FileAccessI implements Serializable{ ~-XOvKJb
YMc8Q\*B
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 X+]L-o6I2
RandomAccessFile oSavedFile; ~q0I7M
long nPos; [,OJX N-4s
W]@gQ(Ef
'GEBxNH:
public FileAccessI() throws IOException _u:>1]
{ wF|0n t
this("",0); Yw$a{5g
} UJee&4C-y
82j'MgGP
(Oxz'#TX
public FileAccessI(String sName,long nPos) throws IOException A[u)wX^`f^
{ Vk MinE
oSavedFile = new RandomAccessFile(sName,"rw"); 5x*5|8
this.nPos = nPos; f,Sth7y
oSavedFile.seek(nPos); ksB
} q+YuVQ-fx
;j>*;Q`
0lX)Cl
public synchronized int write(byte[] b,int nStart,int nLen) mgi,b2
{ [<]Y+33
int n = -1; Uby,Tu
try{ *)MX%`Z}
oSavedFile.write(b,nStart,nLen); <lC]>L
n = nLen; V~/.Y&WN
} Sg-g^dIN1
catch(IOException e) ,\BVV,
{ IZv~[vi_
e.printStackTrace (); 8|1`Tn}o
} 5;X {.2
c u\ls^
2{Wo-B,wt~
return n; ~R :<Bw
} 7IA3q{P
V -q%r
E|pk.
} VLf g[*k
`@h:_d
m_cO<LB
/* DZ^=*.
**SiteInfoBean.java X Y~;)<s_
*/ .qSBh hH\
package NetFox; "Kyifw?
/nc~T3j
%0vTA_W
public class SiteInfoBean { ;(K
! mm5I#s
q\a[S*
private String sSiteURL; //Site's URL KR&s?
private String sFilePath; //Saved File's Path dSwm|kIa
private String sFileName; //Saved File's Name J#0GlK@"
private int nSplitter; //Count of Splited Downloading File 2< p{z
I^WIa"u_
#MUiL=
public SiteInfoBean() JxjP@nr
{//nSplitter的缺省值为5 #:$O=@@?M
//default value of nSplitter is 5 k]Zo-xh4
this("","","",5); #;d)?
} |</"N-#S
s0r"N7~
([Ebsj
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9u?(^(.
{ g]za"U|g
sSiteURL= sURL; HzE1r+3Q@
sFilePath = sPath; WNhbXyp_
sFileName = sName; H6_xwuw:
this.nSplitter = nSpiltter; [!G)$<
4RhR[
+)gGs#2X
} Wdo#?@m
,E&Bn8L~O
u,fA!
public String getSSiteURL() prZ55MS.
{ qtHfz"p
return sSiteURL; +O'vj
} {1~9vHAZ
9SY(EL
JX{KYU
public void setSSiteURL(String value) .8]Y-
{ 6_*!|g
sSiteURL = value; Sr&T[ex,.
} N=#4L$@-
Id%_{),HX
}&1Iyb
public String getSFilePath() *wwhZe4V
{ yLW/ -%I#u
return sFilePath; $_)=8"Sn
} ,<sm,!^<r
{DT4mG5
eZNitGaU
public void setSFilePath(String value) DF'8GF&Rp
{ nX._EC
sFilePath = value; 6yI}1g
} k,rWa
FSU<Y1|XM
H>.B99vp
public String getSFileName() >dk9f}7-
{ ('t kZt%8
return sFileName; >!}`%pk(
} QsOhz
=Ey`M#t;
n>P!u71
public void setSFileName(String value) Noh?^@T`Ov
{ IZ8y}2
sFileName = value; OC_M4{9/
} J3G7zu8
XrS\+y3
L,~MicgV
public int getNSplitter() ^uW%v2
{ uUG*0Lj
return nSplitter; !9r:&n.\
} oEu>}JD
h>wcT VF
m"Qq{p|'
public void setNSplitter(int nCount) ^mg*;8eGa
{ [T`}yb@
nSplitter = nCount; 3sFeP&
} 8Mu;U3cIW
} U<47WfcW
BDe]18X
#dc1pfL!y{
/* )p8I@E
**Utility.java ]TSg!H
*/ m_*R.a
package NetFox; .#fPw_i
:[sOKV i
|y"jZT6R}t
public class Utility { ?z/Vgk+9|
`tE^jqrke5
gi]ZG
public Utility() EvE,Dm?h
{ WJ+>e+
Rg* J}
$ [7 Vgs
} k=/eM$":
g{>^`JtP
//线程睡眠 5+P@sD
public static void sleep(int nSecond) gLQ #4H
{ ^7aN2o3{
try{ >fzwFNdo
Thread.sleep(nSecond); sG,+
} [$a<b/4
catch(Exception e) @(:v_l
{ hVP IHQt
e.printStackTrace (); n#*`!#
} ~|lIC !q
} kIvvEh<L=
<\@1Zz@ms
//日志 }B q^3?,#{
public static void log(String sMsg) 47UO*oLS
{ T&xt`|
System.err.println(sMsg); MJ\[Dt
} 6T+
~p*1:ij
Pxhz@":[
public static void log(int sMsg) z^W$%G
{ l#bAl/c`
System.err.println(sMsg); 5PZN^\^
} ?znSx}t
} `cr(wdvI
[pgZbOIN37
]hE="z=n
/* @Bs0Avj.
**TestMethod.java 4h|dHXYZ
*/ _+w/ pS`M
package NetFox; %f&< wC
"tu*YNP\Q
5Qa zHlJ
public class TestMethod { :0^s0l
5j^NV&/_
w([$@1]
public TestMethod() sR=/%pVN
{ ///xx/weblogic60b2_win.exe k0H#:c}
try{ z.)p P'CJo
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *P2[qhP2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |n6Eg9
SiteFileFetch fileFetch = new SiteFileFetch(bean); >dQK.CG
fileFetch.start(); Bct"X#W|&
} N.j "S'(i
catch(Exception e){e.printStackTrace ();} |(% u}V?
i0pU!`0
*'ZN:5%H
} x5Zrz<Y$w
hu5!ev2
A^Cj1:,
public static void main(String[] args) ohQAA h
{ 4TRG.$2[
new TestMethod(); l@~LV}BI
} 3HiFISA*
} .mxTfP=9
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