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)); sF, uIr/
} Xd5! Ti}
for(int i=0;i<nEndPos.length-1;i++) &?fvt
{ !cv6 #:
nEndPos = nStartPos[i+1]; =NI.d>kvC
} E{?L= ^cU
nEndPos[nEndPos.length-1] = nFileLength; gx&\Kw6HM
} N_*u5mfQX
} TosPk(o(
]r]+yM|
-y9Pn>~V
//启动子线程 Ed8U;U b
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fa/P%9db
for(int i=0;i<nStartPos.length;i++) >J?jr&i
{ eF*TLI<[^I
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fjF!>Dy
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), G<Th<JF)Q
nStartPos,nEndPos,i); 'XG:1Bpm
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h7)VJY
fileSplitterFetch.start(); 6Eij>{v
} FDZeIj9uF
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -+`az)lrp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9 #.<E5:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |A2W8b {]
nEndPos = " + nFileLength); &P{o{
// fileSplitterFetch[nPos.length-1].start(); 2"B}}
LJ:mJ#
7v.#o4nPK
//等待子线程结束 D6"~fjHh
//int count = 0; [+Yl;3&]
//是否结束while循环 (bM)Nd
boolean breakWhile = false; IH*U!_ `
`,hW;p>-
5>0\e_V
while(!bStop) 0]/,m4a#n
{ 5?S{W
write_nPos(); :4Id7Ce
Utility.sleep(500); _wIBm2UO
breakWhile = true; 8b8e^\l(
z|taa;iM
JuKk"tr~RB
for(int i=0;i<nStartPos.length;i++) #3AYz82w
{ w+URCj
if(!fileSplitterFetch.bDownOver) )UxQf37
{ "Yc^Nc
breakWhile = false; L5i#Kh_
break; !- Cs?
} 8T!fGzHx
} $4#=#aKW.
if(breakWhile) p3>Q<
break; mdmZ1:PBM
YMd&To0s
a 5~G
//count++; /gMa"5?,
//if(count>4) OtrXYiKB
// siteStop(); #VP-T; Ahe
} 8ItCfbqa6
?[a7l:3-[
|>jqH @\P
System.err.println("文件下载结束！"); RPofa+
} 4O5n6~24
catch(Exception e){e.printStackTrace ();} \#IJ=+z
} c%6 @ z
Y`E{E|J
Xs.$2
//获得文件长度 &mO/u=u
public long getFileSize() 6&/ Ew4 e
{ P@o,4\;K
int nFileLength = -1; y^0HCp{
try{ (mOqv9pn
URL url = new URL(siteInfoBean.getSSiteURL()); e|OG-t[$*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fwar8 i1
httpConnection.setRequestProperty("User-Agent","NetFox"); C.Wms}XA
DKaG?Y,*p
mfp`Iy"}+
int responseCode=httpConnection.getResponseCode(); ~(*co[_
if(responseCode>=400) 6qmo ZAg
{ E#&c]9QM75
processErrorCode(responseCode); 4F1.D9u
return -2; //-2 represent access is error 3thG*^C5
} gz)wUQ|W
6@,'m
E@'CU9Fo
String sHeader; wXIe5
y5Z<uwXc
3f7t%
for(int i=1;;i++) o0-fUCmC
{ KNUMz4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;_Of`C+
//Utility.log(in.readLine()); s$+: F$Y0
sHeader=httpConnection.getHeaderFieldKey(i); -?2&5YB
if(sHeader!=null) US*<I2ZLh
{ jmA{rD W
if(sHeader.equals("Content-Length")) \V!X& a
{ G74a9li@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); B[U.CAUn
break; ,sRrV $,"
} O. .@<.
} ~[ ks|
else Cs~\FI1wR
break; L2V $%*6
} aLyhxmn ^)
} d q+7K
catch(IOException e){e.printStackTrace ();} 4.Jaw+
catch(Exception e){e.printStackTrace ();} HnKF#<
>R'VY "\
y>pq*i
Utility.log(nFileLength); FclSuQWti
yg]nS<K~4
[gg7Z|Hu
return nFileLength; 51FK~5
} -+S~1`0
j8ohzX[Y
/9vMGef@
//保存下载信息（文件指针位置） 59%f|.Z)
private void write_nPos() s+\qie
{ XQg%*Rw+t
try{ cO"Xg<#y
output = new DataOutputStream(new FileOutputStream(tmpFile)); >-./kI "
output.writeInt(nStartPos.length); -T>wi J
for(int i=0;i<nStartPos.length;i++) `QyALcO
{ J1v0 \
// output.writeLong(nPos); 0z<]\a4
output.writeLong(fileSplitterFetch.nStartPos); 5M.n'*
output.writeLong(fileSplitterFetch.nEndPos); 4|o{_g[
} aR(Z~z;C
output.close(); q0KXuMK
} J9KLO=
catch(IOException e){e.printStackTrace ();} bZ@53
catch(Exception e){e.printStackTrace ();} Xy(SzJ%
} X7B)jH%N
pmpn^ZR
sR0e&Y
//读取保存的下载信息（文件指针位置） qKb-aP-
private void read_nPos() !kk %;XSZ
{ gm%bxr@X~
try{ Y_ ;i
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); x#}eC'Q
int nCount = input.readInt(); 1 0Tg> H
nStartPos = new long[nCount]; Gv2./<{#
nEndPos = new long[nCount]; PTc\I
for(int i=0;i<nStartPos.length;i++) G<WDyoN=O
{ @W5hrei
nStartPos = input.readLong(); JV6U0$g_S
nEndPos = input.readLong(); :tS>D5dz(
} zZjLt1
input.close(); d}B_ll#j-
} :$Di.|l@7
catch(IOException e){e.printStackTrace ();} ,I:m*.q
catch(Exception e){e.printStackTrace ();} +>9^])K|
} OD!CnK
ug3lMN4UX
yp/V8C
private void processErrorCode(int nErrorCode) JU,ROoz(
{ Hn]n]wsLy
System.err.println("Error Code : " + nErrorCode); &DhA$o"'
} z o))x(
QRG)~
GWE0 UO}
//停止文件下载 R(Pa Q
public void siteStop() ^HN
{ JX,#W!d
bStop = true; ~^5n$jq
for(int i=0;i<nStartPos.length;i++) 9QQ@Y}
fileSplitterFetch.splitterStop(); t>|N4o
)/i|"`)>_
1^"aR#
} WuQ<AS=
} #1hz=~YO
//负责部分文件的抓取 H?bsK~
**FileSplitterFetch.java v+_Y72h*a
*/ )B5gs%u]
package NetFox; <XcMc<h~
yt#;3
xgw)`>p,W
import java.io.*; Bst>9V&R
import java.net.*; 7a_n\]t465
d"`>&8*
+6Fdi*:
public class FileSplitterFetch extends Thread { &)}:Y!qiu
>xMhA`l
eeTaF!W
String sURL; //File URL ~I^[rP~
long nStartPos; //File Snippet Start Position (GOrfr
long nEndPos; //File Snippet End Position "?(Fb_}i
int nThreadID; //Thread's ID \kGtYkctZ
boolean bDownOver = false; //Downing is over 7tO$'q*h
boolean bStop = false; //Stop identical nVA'O
FileAccessI fileAccessI = null; //File Access interface 2o}G<7r
NcMq>n
, p=8tf#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException IMw)X0z
{ %1+~(1P
this.sURL = sURL; N}<U[nh'
this.nStartPos = nStart; tZ24}~da
this.nEndPos = nEnd; KK3xz*W0
nThreadID = id; Wk#-LkI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 tSLl'XeN
} ~vZzKRVS
u,9U0ua@;
&fhurzzAm
public void run() ]8nm9qmF<
{ e>9{36~jh
while(nStartPos < nEndPos && !bStop) !td.ks0
{ _llaH
/ H/Ne )r
=QO[zke:
try{ fv'P!+)t
URL url = new URL(sURL); b'"%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;pK"N:|
httpConnection.setRequestProperty("User-Agent","NetFox"); c)YGwkY,,
String sProperty = "bytes="+nStartPos+"-"; #;\;F PuZ
httpConnection.setRequestProperty("RANGE",sProperty); `%I{l
Utility.log(sProperty); ##ea-"m8
#/=yz<B
3t6'5{
InputStream input = httpConnection.getInputStream(); yk6UuI^/
//logResponseHead(httpConnection); #{cpG2Rs
=zGz|YI*?
Rk0rHC6[
byte[] b = new byte[1024]; Y[]t_o)
int nRead; {NqGWkGt*b
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) w:@M|O4`
{ <:t\P.
nStartPos += fileAccessI.write(b,0,nRead); +ANIm^@
//if(nThreadID == 1) S.>9tV2Ca
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +-137!x\q
} #$)rwm.jW?
H pfI
=W^L8!BE'
Utility.log("Thread " + nThreadID + " is over!"); Z6ex<[`I
bDownOver = true; ?kefRev<#h
//nPos = fileAccessI.write (b,0,nRead); R6.#gb8^oS
} +34jot.!
catch(Exception e){e.printStackTrace ();} )BrqE uX@"
} Gnq~1p5^
} 2b` M(QL
`.-C6!
5-po>1g'
//打印回应的头信息 y_r6T XnGL
public void logResponseHead(HttpURLConnection con) X*):N]
{ }#^F'%zf
for(int i=1;;i++) {XW>:EU'N
{ ->{WO+6(
String header=con.getHeaderFieldKey(i); /T'nY{
if(header!=null) bG?[":k
//responseHeaders.put(header,httpConnection.getHeaderField(header)); t!C-G+It
Utility.log(header+" : "+con.getHeaderField(header)); F+r6/e6a
else 2p[3Ap
break; {<8#T`I
} ] 6B!eB !
} xq*yZ5:5Jo
B1.@K}
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public void splitterStop() }'- )
{ -*r';Mz;
bStop = true; E/ )+hK&
} 5E|2S_)G
Z:Am\7 I
KgSxF#
} !!>G{
bm?TMhC
!d_A?q'hN
/* PdnK@a
**FileAccess.java 8~>3&jX
*//文件访问(定位，写) e/Y+S;a
package NetFox; x{5*%}lX8
import java.io.*; yp/*@8%_E
Rw%KEUDm
|XZf:}q5:
public class FileAccessI implements Serializable{ u9(AT>HxT
C(hg"_W ou
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 + k:?;ZG
RandomAccessFile oSavedFile; ?Fv(4g
long nPos; Lo4t:H&
h^,a 1'
1jVcL)szU
public FileAccessI() throws IOException %9M49s
{ x$I>e
this("",0); MG>;|*$%
} ,//=yW
=G6@:h=
#n r1- sf|
public FileAccessI(String sName,long nPos) throws IOException M$9h)3(B
{ y0]O 6.{
oSavedFile = new RandomAccessFile(sName,"rw"); sqRuqUj+
this.nPos = nPos; G=e[TR)i
oSavedFile.seek(nPos); :8 :>CHa
} RPwSo.c4
Cv33?l-8%_
*^()el,d
public synchronized int write(byte[] b,int nStart,int nLen) 4+"SG@i`W
{ $la,_Sr
int n = -1; Y.J$f<[R
try{ ~~mQ
oSavedFile.write(b,nStart,nLen); C? S%fF
n = nLen; *1Q?~
} GYO"1PM
catch(IOException e) 9:s!#FYFM
{ ?=&*6H_v
e.printStackTrace (); =j-{Mxb3
} IZLX[y
O8%/Id
KW\`&ki
return n; \)*qW[C$a
} pz+#1=b]
?*=Jq
tTal<4
} (B5G?cB9
L\I/2aiE
~MF. M8
/* 1)y}.y5S
**SiteInfoBean.java (X/JXu{
*/ "^`AS"z'
package NetFox; m{|n.b
A\>qoR!Y
&/p9+gd
public class SiteInfoBean { PR0]:t)E
; V8 =B8w
t)h3GM
private String sSiteURL; //Site's URL X@rAe37h+
private String sFilePath; //Saved File's Path RWYA`
private String sFileName; //Saved File's Name ="4)!
private int nSplitter; //Count of Splited Downloading File KMa?2cJH#
%o>1$f]
q_bB/
public SiteInfoBean() E),T,
{//nSplitter的缺省值为5 `fXcW)
//default value of nSplitter is 5 A7se#"w
this("","","",5); O#g31?TO
} lf 3W:0K
OxRzKT
*&s_u)b
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) FsjblB3?E
{ &>SE9w/?o
sSiteURL= sURL; r.[kD"l
sFilePath = sPath; .vg;K@{
sFileName = sName; oVdmgmT.Y
this.nSplitter = nSpiltter; 3f0RMk$pH
TD'1L:mv
WD<M U ]
} ET4YoH>
3~ylBJJ
occ}|u
public String getSSiteURL() Pg7/g=Va
{ i{.!1i:
return sSiteURL; [||$1u\%
} raCxHY
B^Vb=* QRo
%5b2vrg~*
public void setSSiteURL(String value) 5K0Isuu>>
{ 74_ji!
sSiteURL = value; e([}dz
} Ad[-YT
6v-h!1p{u
YvonZ
public String getSFilePath() p4=^ UP
{ z@2NAC
return sFilePath; nL9m{$Zv
} k2~j:&p
OvkYzI`
yfj<P/aA+
public void setSFilePath(String value) u7K0m! jW
{ 1:?WvDN=
sFilePath = value; \7RP6o
} qbjRw!2?w
:7'anj
\O[Cae:^?
public String getSFileName() xGjEEBL
{ [dL#0~CL$
return sFileName; rLVS#M#&e>
} q*>`HTPcU
O3S_P]{*ny
mU;TB%#)
public void setSFileName(String value) 8d-_'MXk3
{ dbw`E"g
sFileName = value; Y%2<}3P
} J}BS/Tr}=
"~tEmMz
%%*t{0!H+
public int getNSplitter() l&zd7BM9(
{ a4?:suX$
return nSplitter; P:=3;d{v
} J^U#dYd
*g7dB2{
>>p3#~/
public void setNSplitter(int nCount) tcfUhSz,I
{ Y>r9"X|&H
nSplitter = nCount; Pt E>08
} R ~#\gMs
} f5AK@]4G
AkGCIn3
5E$)Ip
/* L0}"H .
**Utility.java #,Rmu
*/ w _n)*he)z
package NetFox; z"|^Y|`m
^b'[81%
A>Js`s
public class Utility { C]82Mt
Jjv, )@yo
9M<{@<]dm
public Utility() d+$a5 [^9
{ bX8Bn0#a+
+`zM^'^$
-3A#a_fu
} xI$B",?(
U)2\=%8
//线程睡眠 M '[.ay
public static void sleep(int nSecond) ,u/GA<'#M
{ CtS*"c,j
try{ nI&Tr_"tm
Thread.sleep(nSecond); 72.ZE%Ue
} WI' ;e4
catch(Exception e) w[t!?(![>
{ ):1NeJOFF
e.printStackTrace (); p3&w/K{L6w
} G}d@^9FkE
} r\Zz=~![<
s#>Bwn&b)
//日志 j*xxOwf
public static void log(String sMsg) xDm^f^}>
{ =JY9K0S~
System.err.println(sMsg); ex1bjM7
} 4$C:r&K
__OD^?qa
d H]'&&M
public static void log(int sMsg) 'Tj9btM*cL
{ &^92z:?
System.err.println(sMsg); ZBi|BD
} q<dZy? f
} x xWnB
a2/!~X9F
g^/
/* 3+rud9T
**TestMethod.java adRvAq]mA
*/ %Sf%XNtu
package NetFox; lOYzo
1*,f
'(4$h3-gv7
public class TestMethod { jNBvy1
\hoYQK j
lku}I4
public TestMethod() `C9/=
{ ///xx/weblogic60b2_win.exe eJlTCXeZ|
try{ 3!ZndWSHV
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); bd_&=VLTC
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); x8+W9i0[1
SiteFileFetch fileFetch = new SiteFileFetch(bean); .IXkdy
fileFetch.start(); |]y]K%
} v!JQ;OX
catch(Exception e){e.printStackTrace ();} BxVo>r
0rP`BK|
bS[;d5
} p'tB4V qT
5ELKL#(
>,wm-4&E
public static void main(String[] args) nO.RB#I$F
{ d2Pqi* K
new TestMethod(); ( E;!.=%
} ~H`~&?
} 3Uw}!>`%
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