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)); =I.uf
} =67ab_V
for(int i=0;i<nEndPos.length-1;i++) ,kQCCn]
{ 2y"L&3W
nEndPos = nStartPos[i+1]; ] /"!J6(e
} *P01 yW0
nEndPos[nEndPos.length-1] = nFileLength; Yt!o Hn
} :Bh7mF-1
} QBYY1)6S,
1La?x'{2MP
xcQD]"
//启动子线程 *Uw"`l
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; gB<1;_KW
for(int i=0;i<nStartPos.length;i++) 9^?2{aP%
{ SuR+Vv
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d53Eu`QW?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), w#d7
nStartPos,nEndPos,i); !U7}?i&H
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )H1\4LeP
fileSplitterFetch.start(); $RA+StF!]
} SpO%nZ";g8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 01n7ua*XX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @?n~v^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", r1&eA%eh
nEndPos = " + nFileLength); {i<L<Y(3
// fileSplitterFetch[nPos.length-1].start(); |4C5;"Pc
<YM!K8hu$
lyS`X
//等待子线程结束 Fy*t[>
//int count = 0; `t7z LC^c
//是否结束while循环 K_Pbzj4(P
boolean breakWhile = false; csFLBP
%N#A1
'u#c_m!9
while(!bStop) 5oe{i/#di
{ F2>W{-H+
write_nPos(); .~a.mT
Utility.sleep(500); < ZG!w^
breakWhile = true; \nUJ)w
>:bXw#w]
TVZf@U
for(int i=0;i<nStartPos.length;i++) +<T361eyY
{ _<6E>"*m
if(!fileSplitterFetch.bDownOver) `l'Ine11
{ *x/H
breakWhile = false; +ovT?CMo
break; R('\i/fy
} 'kSm}}y
} s-4qK(ml-
if(breakWhile) >l b9j>
break; W%1/:_
|fB/hs \
l h?[wc
//count++; 3V]08
//if(count>4) )b~+\xL5J
// siteStop(); hZ|8mV
} % kaV?j
M_O)w^ '
~#dfZa&
System.err.println("文件下载结束！"); *EPJeblAV
} ?X+PNw|pf
catch(Exception e){e.printStackTrace ();} C1uV7t*\
} t=\ ffpA
Mn 8| Knh
9JqT"zj
//获得文件长度 ]*X z~Ox2
public long getFileSize() #h#_xh'
{ bt"5.nm
int nFileLength = -1; Jsa;pG=3&
try{ :(K JLa]
URL url = new URL(siteInfoBean.getSSiteURL()); 5`6U:MDq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gL&)l!2Y
httpConnection.setRequestProperty("User-Agent","NetFox"); e**5_L
\('WS[$2
?^ R"a##
int responseCode=httpConnection.getResponseCode(); /&E]qc*-p
if(responseCode>=400) Uuktq)NU
{ I%jlM0ZUI"
processErrorCode(responseCode); ub2B!6f a
return -2; //-2 represent access is error y\n#`*5k
} "[sr0'g:
vs{VRc
dtBr#Te
String sHeader; fRwr}n'
XaaR>HljJ
Rw<O%i5/d
for(int i=1;;i++) .7+"KP:
{ '(zP;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 09=w
//Utility.log(in.readLine()); _U o3_us
sHeader=httpConnection.getHeaderFieldKey(i); w^ X@PpP
if(sHeader!=null) E_0i9
{ ~i]4~bkH2
if(sHeader.equals("Content-Length")) sw50lId
{ YlXqj\a
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `[h&Q0Du6
break; {Q)sR*d
} W!|l_/L'
} sT,*<^
else L=5Y^f'aU
break; a{Y8hR
} Rl (+TE
} /2cn`dR,
catch(IOException e){e.printStackTrace ();} wauM|/KG
catch(Exception e){e.printStackTrace ();} D|2lBU
hP_{$c{4:g
$,o@&QT?AT
Utility.log(nFileLength); v <m=g!
sRQ4pnnrn
+.v+Opp,
return nFileLength; Pk6_1LV
} paUJq?Af
zhh6;>P
z`YAOhD*h4
//保存下载信息（文件指针位置） ?z3|^oU~d
private void write_nPos() U^Iq]L
{ Y2|c;1~5$
try{ sfp.>bMj
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9Qq%Fw_
output.writeInt(nStartPos.length); Icx)+Mq
for(int i=0;i<nStartPos.length;i++) aNgJm~K0P
{ L?(m5u~b
// output.writeLong(nPos); 16"L;r
output.writeLong(fileSplitterFetch.nStartPos); k;<F33v;Mh
output.writeLong(fileSplitterFetch.nEndPos); xv7nChB
} {5SJ0'.B2g
output.close(); 5*O]`Q7
} Mn*5oH
catch(IOException e){e.printStackTrace ();} uFG ;AY|
catch(Exception e){e.printStackTrace ();} 0xV[C4E[6
} ?SX0e(+}}
1]aya(
,w,)n^
//读取保存的下载信息（文件指针位置） +$R%Vbd
private void read_nPos() _@Y17L.
{ &D`$YUl@
try{ ]_hXg*?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); s5ILl wr
int nCount = input.readInt(); F~3 &@TWi
nStartPos = new long[nCount]; 5IP@_GV|
nEndPos = new long[nCount]; R+Rb[,m
for(int i=0;i<nStartPos.length;i++) 5 HN,y
{ T'7x,8&2|
nStartPos = input.readLong(); R7Ns5s3X
nEndPos = input.readLong(); \r}*<CRr6
} ;nb>IL
input.close(); GFZx[*+%%z
} bQwiJ`B&
catch(IOException e){e.printStackTrace ();} 6MbMAh5>
catch(Exception e){e.printStackTrace ();} OKCX>'j:S
} [ZETyM`
(N{
,-.=]r/s
private void processErrorCode(int nErrorCode) [[Usrbf
{ 9!wm`'G8
System.err.println("Error Code : " + nErrorCode); ,]=Qgn
} aIE\B4w
eD N%p
GEAVc9V
//停止文件下载 NTSKmCvQG
public void siteStop() HgRfMiC
{ ]2xoeNF/W{
bStop = true; kN*\yH|
for(int i=0;i<nStartPos.length;i++) DO? bJ01
fileSplitterFetch.splitterStop(); =e]Wt/AQ
]K%D$x{+\
Ay\!ohIS3
} Mp^U)S+
} nHB`<B
//负责部分文件的抓取 nmrdqSV
**FileSplitterFetch.java @3>nVa
*/ !7anJl
package NetFox; MM Nz2DEy[
JmVha!<qk
;%PdSG=U
import java.io.*; }{e7wqS$&,
import java.net.*; G$ Ii
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Gp))1b';
public class FileSplitterFetch extends Thread { ?[q.1O
&?7+8n&+
:=%`\\
String sURL; //File URL XcQ'(
long nStartPos; //File Snippet Start Position !O#NP!
long nEndPos; //File Snippet End Position 9rQpKq:# E
int nThreadID; //Thread's ID jz$83TB-
boolean bDownOver = false; //Downing is over bq`0$c%hN
boolean bStop = false; //Stop identical h>K%OxR
FileAccessI fileAccessI = null; //File Access interface .e2K\o
;?:X_C
?ik6kWI
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException veGRwir
{ ]ipltR7k
this.sURL = sURL; GGn/J&k
this.nStartPos = nStart; 9!|.b::
this.nEndPos = nEnd; wz]OM
nThreadID = id; L}%4YB
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ci^tP~)&"
} rDWqJ<8
W= \gPCo
y'pX/5R0
public void run() #oD*H:%*
{ ^k}jPc6
while(nStartPos < nEndPos && !bStop) #&c}in"!
{ }!g^}BWWp
<ba+7CK]w
u<{uUui}$v
try{ iG;GAw|E
URL url = new URL(sURL); Xa32p_|5~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @Y2&v956
httpConnection.setRequestProperty("User-Agent","NetFox"); ]Q\/si&
String sProperty = "bytes="+nStartPos+"-"; ?{I]!gI
httpConnection.setRequestProperty("RANGE",sProperty); zbL6TP@=
Utility.log(sProperty); OQh(qa
zos#B30
@VcSK`
InputStream input = httpConnection.getInputStream(); T5di#%: s
//logResponseHead(httpConnection); 2*1s(Jro
~2*8pb 4
1(z+*`"WB&
byte[] b = new byte[1024]; ocT.2/~d
int nRead; l~Sn`%PgA
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) sGD b<
{ Qf]ACN
nStartPos += fileAccessI.write(b,0,nRead); I~>L4~g)
//if(nThreadID == 1) h47l;`kD-#
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #0j,1NpL
} xN#. Pm~
B]YY[i
$?u ^hMU=
Utility.log("Thread " + nThreadID + " is over!"); i bwnK?ZA
bDownOver = true; Ka\%kB>*`
//nPos = fileAccessI.write (b,0,nRead); .v:K`y;f\(
} ]%5DuE\M8\
catch(Exception e){e.printStackTrace ();} W=EvEx^?%
} AyMMr_q
} hol54)7$3:
Ng3MfbFG
3#ua
//打印回应的头信息 (_ElM>
public void logResponseHead(HttpURLConnection con) fw1g;;E
{ [UHDN:y
for(int i=1;;i++) cHMS[.=;
{ Y+tXWN"8
String header=con.getHeaderFieldKey(i); nUvxO `2
if(header!=null) b%<i&YY#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (U |[C*
Utility.log(header+" : "+con.getHeaderField(header)); UC34AKm
else Py8<db%
break; J$?*qZ(oO
} 8vcV-+x
} }GCt)i_
Oj*3'?<7=
-)tu$W*
public void splitterStop() r='"X#CmV/
{ dviL5Eaj
bStop = true; mu/O\'5
} "3v[\M3
98os4}r
D`lTP(] y
} /0mbG!Ac
+BRmqJ3
HX{O@
/* >]k'3|vV
**FileAccess.java TK;*:K8oe
*//文件访问(定位，写) T}X#I'Z
package NetFox; +M6qbIO
import java.io.*; #<bt}Tht
@hiwq7[j
4l$(#NB<
public class FileAccessI implements Serializable{ wvm`JOP:A
|Y!#`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Y$ ;C@I
RandomAccessFile oSavedFile; ']+-u{+#
long nPos; Q-%Q7n'c
^Q]*CU+C
s45Y8!c
public FileAccessI() throws IOException Yo c N@s
{ #s1O(rLRl
this("",0); vvLm9Tw
} "|<\\HR
_gB`;zo
lu(<(t,Lbs
public FileAccessI(String sName,long nPos) throws IOException Cd#>,,\z
{ 1@kPl[`p'
oSavedFile = new RandomAccessFile(sName,"rw"); jl=<Q.Mm7
this.nPos = nPos; 5o5y3ibQ
oSavedFile.seek(nPos); /GNRu
} a'ViyTBo
F t%f"Z
K^k1]!W=
public synchronized int write(byte[] b,int nStart,int nLen) h@T}WZv
{ 7{:| )
int n = -1; RR><so%
try{ J56+eC(
oSavedFile.write(b,nStart,nLen); B3'qmi<
n = nLen; @xW)&d\'
} ,ORZtj
catch(IOException e) &2{h]V6
{ -L6 rXQV@j
e.printStackTrace (); X|H%jdta
} su(y*187A
0iW]#O/
&eT)c<yhyK
return n; 'N],d&fu^^
} Uq&ne1
@YP\!#"8
f8)D|
} b1jh2pG(V
0i9y-32-
jNV2o
/* 'z2}qJJ)
**SiteInfoBean.java UnZ*"%
*/ }.7!@!q.
package NetFox; 0%}$@H5i
_n2PoE:5@P
@<\f[Znto
public class SiteInfoBean { Y2j>lf?8
<oPo?r|oM|
VY@uQ#&A
private String sSiteURL; //Site's URL r^&{0c&o
private String sFilePath; //Saved File's Path 46*o_A,"
private String sFileName; //Saved File's Name tn;e PcU
private int nSplitter; //Count of Splited Downloading File 6z"fBF
$GUSTV
XZA3TZ
public SiteInfoBean() fSl+;|Kn
{//nSplitter的缺省值为5 >\8Bu#&s4
//default value of nSplitter is 5 tuK"}HepB
this("","","",5); =R!=uml(
} +M (\R?@gr
Fm{Ri=X<:
<dDGV>n4;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) } O9q$-8!
{ OibW8A4Z1
sSiteURL= sURL; ,Z#t-?
sFilePath = sPath; \*!?\Ko`W
sFileName = sName; QR'"Zw&q5/
this.nSplitter = nSpiltter; /9|1eSUa
X\hD4r"
)m"NO/sJ2
} (zBa2Vmmv
._=Pa)T
6 EE7<&
public String getSSiteURL() [Zl
{ Et%s,zeA{2
return sSiteURL; x';6
} <[?oP[ j
9C$b^wHd
8=T;R&U^M
public void setSSiteURL(String value) pQ*9)C
{ U#+S9jWe
sSiteURL = value; E$34myOVf
} iquB]z'
"a-Ex ]
7s,IT8ii
public String getSFilePath() t'_Hp},
{ "}Ch2K
return sFilePath; 9]VUQl9gh
} >z h
]o_Z3xXUa
zVZZdG~8
public void setSFilePath(String value) Q4TI '/
{ EkEM|<GNd
sFilePath = value; AASw^A3p
} z*YkD"]B
%z J)mOu
NM/?jF@j*
public String getSFileName() 5Qo\0YH
{ ~LuZpV
return sFileName; N/TUcG|m\
} }qG{1Er
&'N{v@Oi)
d%81}4f:
public void setSFileName(String value) c7q1;X{:
{ %(Nu"3|$K=
sFileName = value; ._~_OVU
} qWHH% L;
/0d_{Y+9
vO%n~l=
public int getNSplitter() p8oOm>B96n
{ x$J1%K*
return nSplitter; 2+TCFpv
} *.ri8
X7?p$!M6;B
9loWh5_1Z
public void setNSplitter(int nCount) |zKe*H/
{ \ZigG{
nSplitter = nCount; S WVeUL#5
} 7qA0bUee5
} cTHSPr?<
xpx=t71Hq
Tw)nFr8oF]
/* `Ff3H$_*
**Utility.java :mXc|W3
*/ ~_QZiuq&
package NetFox; X_ne#ZPl
36*"oD=@
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public class Utility { &&xBq?
'~VKH}b
1LZ?!Lw
public Utility() (#BkL:dg
{ ePq(:ih
v98=#k!F
Mhm3u
} }\:3}'S.$
8E&}+DR?
//线程睡眠 o=_:g >5
public static void sleep(int nSecond) T,@.RF
{ #25Z,UU
try{ 6B)(kPW
Thread.sleep(nSecond); ~.u}v~ F
} h +.8Rl
catch(Exception e) ^&zwO7cS
{ ,G!M?@Q
e.printStackTrace (); 6b~Zv$5^Y-
} ]{{A/ j\
} N#Y%+1
YFv/t=`
//日志 FAfk;<#'n+
public static void log(String sMsg) x9Y1v1!5Pu
{ wdS^`nz|
System.err.println(sMsg); );_g2=:#
} 5DK>4H:
{UX?z?0T
gV$j ]
public static void log(int sMsg) -$f~V\M
{ l)[\TD
System.err.println(sMsg); n1 =B
} q&Y'zyHLP
} gS_)(
l~;H~h!h/
4*}[h9J}\
/* <gF=$u|}3[
**TestMethod.java P9p:x6
*/ SUINV_>7
package NetFox; iZ<^p1i
"CLoM\M)
ym9Z:2g
public class TestMethod { =dx!R ,Bw
_Db=I3.HJ
CL.JalR`b
public TestMethod() BAG) -
{ ///xx/weblogic60b2_win.exe XE* @*
try{ 'iA#lKG
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); GwQW I]
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); k"&loh
SiteFileFetch fileFetch = new SiteFileFetch(bean); =.(yOUI
fileFetch.start(); >A5R
} %@#+Xpa+
catch(Exception e){e.printStackTrace ();} -$**/~0zU
@X4Ur+d
a yn6k=F
} px %xoY
26PUO$&b.
X1&Ug^
public static void main(String[] args) <nlZ?~%}
{ fuSfBtLPR#
new TestMethod(); ^e:C{]S=
} bO 2>ced
} GmP)"@O](;
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