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)); Iw4[D#o
} m al?3*x/
for(int i=0;i<nEndPos.length-1;i++) H]}mg='kI
{ mX%T"_^
nEndPos = nStartPos[i+1]; '=`af>Nc
} TkR#Kzv380
nEndPos[nEndPos.length-1] = nFileLength; cGyR_8:2cv
} Nwo*tb:
} \UP=pT@
2fgYcQ8`
u2S8DuJ
//启动子线程 >K<cc#Aa
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [Z2{S-)UM
for(int i=0;i<nStartPos.length;i++) mM r$~^P:
{ ^-Rqlr,F;
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^3ai}Ei3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^#t6/fY.#
nStartPos,nEndPos,i); #^}s1 4n
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _<GXR ?
fileSplitterFetch.start(); '0=mV"#H{
} n?>|2>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {oS/Xa
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); r~G amjS
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >`l^ C
nEndPos = " + nFileLength); Z*b$&nM
// fileSplitterFetch[nPos.length-1].start(); J|F!$m{
?OPuv5!pI
!+z&] S3s
//等待子线程结束 D~FIv
//int count = 0; Y>T<Qn^D
//是否结束while循环 ::_bEmk
boolean breakWhile = false; J/QqwoR
+k h Tl:
1*e7NJ/.,
while(!bStop) };R2M
{ WL|<xNL
write_nPos(); OnH3Ss$
Utility.sleep(500); )gD2wk(
breakWhile = true; K_n GZ/`[
9I:3
3mHP=)
for(int i=0;i<nStartPos.length;i++) G?,"AA;
{ !*3]PZ25a(
if(!fileSplitterFetch.bDownOver) AV4fN@BX
{ XSCcumde!
breakWhile = false; @ M4m!;rM
break; 4s9.")G
} If]rg+|U
} HRyhq;C
if(breakWhile) p({Lp}'
break; c_>AbF{
]a`"O
E`.:V<KW/
//count++; K"[\)&WBG
//if(count>4) P @J)S ?
// siteStop(); ~xv3R
} ?LJiFG]^m
%Eugy
;n.h!wmJ}
System.err.println("文件下载结束！"); Nobu= Z
} /;TtMQt
catch(Exception e){e.printStackTrace ();} cNikLd~?A
} >5E1y!
;W|GUmADf
R! n7g8I%
//获得文件长度 0176
public long getFileSize() @FZ_[CYg
{ @LFB}B
int nFileLength = -1; t&p I
try{ R)4,f~@"
URL url = new URL(siteInfoBean.getSSiteURL()); >Q'*~S@v3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |#{ i7>2U
httpConnection.setRequestProperty("User-Agent","NetFox"); *VHWvj
A^$xE6t
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int responseCode=httpConnection.getResponseCode(); 8_ascvs5
if(responseCode>=400) j/q&qrlL
{ _;%l~q/
processErrorCode(responseCode); x}O,xquY
return -2; //-2 represent access is error +6}CNC9Mp
} >|`1aCg,
Q"uK6ANp'
*2}f $8
String sHeader; L7nG5i
(>Nwd^
'@ p464
for(int i=1;;i++) :xTm-L
{ }I MV@z B
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;y{(#X#
//Utility.log(in.readLine()); ?S9vYaA$
sHeader=httpConnection.getHeaderFieldKey(i); k ]T
if(sHeader!=null) .XkD2~;
{ +sTPTCLE
if(sHeader.equals("Content-Length")) =y(*?TZH
{ yye5GVY$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); p] N/]2rR
break; ? HNuffk
} `>b,'u6F
} Qg]A^{.1
else !G6h~`[
break; ,j9?9Z7R
} ._t1eb`m{
} {-MjsBR
catch(IOException e){e.printStackTrace ();} fFoZ!H
catch(Exception e){e.printStackTrace ();} 19-V;F@;
m>F:dI
-/0aGqY
Utility.log(nFileLength); QN?EI: q=
j:>0XP
R#.H&#
return nFileLength; e2K9CE.O
} *-(o. !#1
[clwmx
FzP1b_i
//保存下载信息（文件指针位置） *0eV9!y
private void write_nPos() Zy.ls&<:
{ *W^a<Zm8>
try{ gHkHAOe/
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?Bl/bY$*h
output.writeInt(nStartPos.length); H'7s`^- >I
for(int i=0;i<nStartPos.length;i++) ()w;~$J
{ `S5::U6E
// output.writeLong(nPos); Sv0?_3C
output.writeLong(fileSplitterFetch.nStartPos); $.:x3TsA
output.writeLong(fileSplitterFetch.nEndPos); }~NXiUe
} w El-
output.close(); CEBG9[|
} [)dIt@Y&j
catch(IOException e){e.printStackTrace ();} ?E(X>tH
catch(Exception e){e.printStackTrace ();} F|R7hqf
} cH4PrMm&
C^5 V
_%Ua8bR$
//读取保存的下载信息（文件指针位置） OB\ZT@l
private void read_nPos() lN8l71N^
{ 1 ?Zw
try{ kM1N4N7
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _d!o,=}
int nCount = input.readInt(); $-~"G,;F
nStartPos = new long[nCount]; #B6f{D[pI
nEndPos = new long[nCount]; #`f{\
for(int i=0;i<nStartPos.length;i++) AL^tUcl
{ W}2!~ep!
nStartPos = input.readLong(); 6O.kKhk
nEndPos = input.readLong(); [~RO9=;L
} _uL[ Z
input.close(); FC6~V6R
} XJKns
catch(IOException e){e.printStackTrace ();} V82I%gPF
catch(Exception e){e.printStackTrace ();} R".$x{{
} ,!GoFu
r>i95u82'
4zt:3bWU
private void processErrorCode(int nErrorCode) 9Li&0E
{ EY3F9h3xM|
System.err.println("Error Code : " + nErrorCode); 4\p%|G^hU
} CY{!BV'
8O(L;&h
*h=>*t?I2
//停止文件下载 q86}'dFw{
public void siteStop() z$}9f*W}B
{ :ir3u
bStop = true; YTmHht{j#
for(int i=0;i<nStartPos.length;i++) )8eb(!}7
fileSplitterFetch.splitterStop(); @Tq-3Um
Lj#xZ!mQS
GvgTbCxnN
} r}^1dO
} 3A[<LnKR^E
//负责部分文件的抓取 N{&Lo}6F
**FileSplitterFetch.java x4g/ok
*/ 9wGsHf8]
package NetFox; X%&7-PO
/DyeMCY-
V=th-o3[
import java.io.*; V9qA'k
import java.net.*; Oq,@{V@)9k
QG~6mvD
j}s/)}n|
public class FileSplitterFetch extends Thread { JC-> eY"O2
d=8.cQL:E
:TR:tf
String sURL; //File URL -y|']I^ &
long nStartPos; //File Snippet Start Position jAue+tB
long nEndPos; //File Snippet End Position )!cucY
int nThreadID; //Thread's ID x3#:C=
boolean bDownOver = false; //Downing is over p~=z)7%e'
boolean bStop = false; //Stop identical ov H'_'
FileAccessI fileAccessI = null; //File Access interface s]0 J'UN
:@"o.8p
Hm!"%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;~djbo0,X
{ Uf]$I`T#
this.sURL = sURL; nTD%i~t~o
this.nStartPos = nStart; 2p#d
this.nEndPos = nEnd; &z5?]`ALu
nThreadID = id; 1%R${Qhr
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ebNRZJ?C,
} m[Ihte->
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MN5}}@
public void run() bc~$"
{ w+)wrJTtm
while(nStartPos < nEndPos && !bStop) zTfjuI|R
{ 0zT-]0
Q&w_kz.
&~/g[\Y
try{ 2RF3pIFrm
URL url = new URL(sURL); LklE,W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]v),[]Xs
httpConnection.setRequestProperty("User-Agent","NetFox"); +/eJ#Xw3u8
String sProperty = "bytes="+nStartPos+"-"; Y3FFi M[s~
httpConnection.setRequestProperty("RANGE",sProperty); T}1"
Utility.log(sProperty); 3`vKEThY)
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km5gO|V>m
InputStream input = httpConnection.getInputStream(); SqRM*Cf=
//logResponseHead(httpConnection); +v5f-CBu
n3&h1-
u9~Ncz
byte[] b = new byte[1024]; :<{15:1
int nRead; qxAh8RR;/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *{k{
{ IDw`k[k
nStartPos += fileAccessI.write(b,0,nRead); z"\w9 @W
//if(nThreadID == 1) ^c(r4#}$"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Pi |Z\j)
} ?u:mscb
HWB\}jcA6u
)4s7,R
Utility.log("Thread " + nThreadID + " is over!"); !v=/f_6
bDownOver = true; @&&}J
//nPos = fileAccessI.write (b,0,nRead); iHf):J?8 y
} zjcSn7iu
catch(Exception e){e.printStackTrace ();} f{O-\
} KehM.c^
} zDtC]y'
>R6mI
zA+0jhuG
//打印回应的头信息 gg^iYTpt
public void logResponseHead(HttpURLConnection con) .E+O,@?<
{ &[j9Up'
for(int i=1;;i++) ')yYpWO
{ Vj1V;dHv
String header=con.getHeaderFieldKey(i); ~}d\sQF.
if(header!=null) A-3^~aEgx
//responseHeaders.put(header,httpConnection.getHeaderField(header)); J(!=Dno
Utility.log(header+" : "+con.getHeaderField(header)); 7A'E+>1d
else e&:%Rr]x
break; L'`Au/%S}
} LJb=9tp~
} d*04[5`
$|&<cenMT
O/ItN5B ;
public void splitterStop() "s]
{ XRQ1Uh6
bStop = true; [_3&
} Zos.WS#
M=95E$6
O`%F{&;29
} -bdWG]w"
m;rr7{7X
8tv4_Lbx
/* C@]D*k
**FileAccess.java Bfo#N31F}
*//文件访问(定位，写) Whp`\E<<
package NetFox; 5bXpj86mY
import java.io.*; P2`F" Qsq
(;05=DsO
m{Uh{G$
public class FileAccessI implements Serializable{ 09P2<oFLn
u9,dSR
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1'("; 0I
RandomAccessFile oSavedFile; .{?;#Cdn
long nPos; F@Wi[K
<o3I<ci6
fJ _MuAv
public FileAccessI() throws IOException L;vglS=l;
{ cmU0=js.
this("",0); BQ[R)o
} `W_&^>yl
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\h s7>5O^K
public FileAccessI(String sName,long nPos) throws IOException -}sMOy`
{ XY9%aT*
oSavedFile = new RandomAccessFile(sName,"rw"); $0P16ZlPC
this.nPos = nPos; eY?OUS
oSavedFile.seek(nPos); ZBx,'ph}4
} F 2zUz[
&FOq c
6(htpT%J
public synchronized int write(byte[] b,int nStart,int nLen) CKe72OC
{ gp 11/.
int n = -1; Q7F4OS5b
try{ m8F \ESL
oSavedFile.write(b,nStart,nLen); e];IQ|
n = nLen; |E$q S)y
} }W!w
catch(IOException e) a;U)#*(5|v
{ JgP%4)]LV
e.printStackTrace (); A/}[Z\C
} }2*qv4},!
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W=+AU!%
return n; XUR#|
} &YD+s%OL
;O~FiA~`c
>j ].`T
} s?1Aj<
hv>Xr=RE
+ `'wY?
/* Gx4uf
**SiteInfoBean.java B%tj-h(a
*/ 3d1xL+
package NetFox; d Efk~V\
]c'EJu
']c;$wP
public class SiteInfoBean { =u0a/2u|
VJW8%s[
@V1FBw9S!@
private String sSiteURL; //Site's URL !nsr( 7X2
private String sFilePath; //Saved File's Path 32anmVnf
private String sFileName; //Saved File's Name P92pQ_W
private int nSplitter; //Count of Splited Downloading File ('BB9#\t
UL&>]aQ
;$$w`LyP
public SiteInfoBean() ds+2z=!!e
{//nSplitter的缺省值为5 _(io8zqe{j
//default value of nSplitter is 5 }7{(o-
this("","","",5); ##F$8d)q
} mAIl)mq|g
2Z<S^9O9
Pd d(1K*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 3^q9ll7Op
{ l6xqc,h!K
sSiteURL= sURL; N~`r;E
sFilePath = sPath; Rw[!Jq
sFileName = sName; 8(q8}s$>
this.nSplitter = nSpiltter; 48J{Y3F
5RO6YxQ
).u>%4=6
} GuL0:,
QL2LIs
F`,bFQ
public String getSSiteURL() myOW^
{ ^Dfqc-]
return sSiteURL; K~^o06 Y
} LSXsq}
5OOXCtIKf
,?%Y*?v
public void setSSiteURL(String value) )ytP$,r![S
{ :AuKQ`c
sSiteURL = value; P&Xy6@%[Z
} ix?Z:pIS0
rXTdhw?+
"av/a
public String getSFilePath() e9S*^2;
{ \fUVWXv
return sFilePath; B"*PBJuOA
} ga;t`5+d
F60m]NUM)c
KqaEHL
public void setSFilePath(String value) K@osD7-
{ =R9`to|
sFilePath = value; _XrlCLp: d
} {Q]7!/>>
Z.aeE*Hs$
Kh&a#~c
public String getSFileName() |Df`Aq(eYJ
{ mc,HliiJ
return sFileName; tI9p2!
} ~G^+.>j
D`B*+
<FZ*'F*M
public void setSFileName(String value) l}g_<
{ Xo.3OER
sFileName = value; vZ=dlu_t
} u^VQwu6?G
d]E.F64{
76c:*bZ
public int getNSplitter() cauKG@:2F
{ 7eZwpg?K
return nSplitter; Tn>L?
} qCm%};yt
$\20Vgu<
0PUSCka'6
public void setNSplitter(int nCount) C'sA0O@O
{ $Nj'_G\}
nSplitter = nCount; _71I9V&
} w>RwEU+w=@
} =fhRyU:C[z
a][Tb0Ox
[Mv'*.7
/* jzZEP4
**Utility.java >DzW OB
*/ '^2bC
package NetFox; "Vwk&~B%
[>QzT"=
*;T HD>
public class Utility { i(q a'*
OG7U+d6
v}^uN+a5
public Utility() v?DA>
{ "(\]-%:7
x.(Sv]+[
zj1_#=]
} pM!cF
<2I<Z'B,e
//线程睡眠 Et)j6xz/F
public static void sleep(int nSecond) 8..g\ZT
{ }.<]A
try{ s8r[U, }(
Thread.sleep(nSecond); }\ya6Gi8
} N&Uqzt*
catch(Exception e) 5VLC\QgK^
{ 6:G::"ew
e.printStackTrace (); IU]@%jA_:A
} eGbjk~,f'
} pr1>:0dg
7 /DDQ
//日志 anUH'mcK*
public static void log(String sMsg) <a D}Ko(
{ 0INlo
System.err.println(sMsg); M8FC-zFs
} RUV:
F @Wb<+0
il:RE8
public static void log(int sMsg) vH?3UW
{ KKwJ=za
System.err.println(sMsg); ~\7peH%
} zids2/_*
} <r8s=<:
U+ief?;4F
{'f=*vMI
/* MrS~u
**TestMethod.java l;;"v) C8
*/ r@H7J 5<Y-
package NetFox; cbX<
KMV&c
j"P}Wn
public class TestMethod { 4Mjcx.21
p+{*&Hm5
hKQg:30<
public TestMethod() *Cx3bg*Gan
{ ///xx/weblogic60b2_win.exe |%Ssb;M
try{ Ky[-ZQQo=5
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); <cR]-Yr~
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); EwOi` g
SiteFileFetch fileFetch = new SiteFileFetch(bean); 53?B.\
fileFetch.start(); W}>wRy
} { Em fw9L
catch(Exception e){e.printStackTrace ();} 4jz2x #T
X>s'_F?
! d" i
} :*E#w"$,j
koOp:7r
kQ $.g<
public static void main(String[] args) 1}I%yOi)
{ ?\T):o;/
new TestMethod(); ?h|w7/9
} gn4Sz")
} N51RBA
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