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)); 'L=g(
} >oLM2VJ
for(int i=0;i<nEndPos.length-1;i++) :qw:)i
{ {T.$xiR
nEndPos = nStartPos[i+1]; cjH ~H8
} V$^x]z
nEndPos[nEndPos.length-1] = nFileLength; x+%lNR
} $g5pKk
} sE]eIN
+Hv%m8'0|
vzs6YsA
//启动子线程 .viA+V
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; m;8_A|$A
for(int i=0;i<nStartPos.length;i++) (9'MdH
{ 7Nx@eoZ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rt t?4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7;c{lQOj}
nStartPos,nEndPos,i); P0UMMn\-#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Bqa%L.N2SS
fileSplitterFetch.start(); '[:].?M
} b-%7@j
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NIQa{R/H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); nn5S7!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", H`B%6S/
nEndPos = " + nFileLength); 5v!Uec'+
// fileSplitterFetch[nPos.length-1].start(); M[HPHNsA&
(w4#?_
S ^2'O7uj
//等待子线程结束 Hq6VwQu?
//int count = 0; Hm%[d;Z7
//是否结束while循环 )` '
boolean breakWhile = false; z{;W$SO 2
!X*L<)=nh
Qa(u+
while(!bStop) eGtIVY/D
{ ]Cbht\Ag"
write_nPos(); ApjLY58=
Utility.sleep(500); dID]{
breakWhile = true; `hI1
hW _NARA
{Yv |C)O
for(int i=0;i<nStartPos.length;i++) OjyS ?YY)b
{ 5N`g
if(!fileSplitterFetch.bDownOver) Pr@EpO
{ mpK|I|-
breakWhile = false; W>;AMun
break; z[IG+2
} Qt]nlui~
} Ba!`x<wa
if(breakWhile) p^\>{
break; ",Ek| z
S7~yRIjB
D;d'ss;
//count++; gd#
//if(count>4) {l\v J#r:
// siteStop(); -V_e=Y<J/
} &hjrJ/'^
VO. Y\8/
LPewoAXO
System.err.println("文件下载结束！"); .E[k}{k,
} ^=.|\ YM
catch(Exception e){e.printStackTrace ();} kX5v!pm[
} ag[yM
c\]h YKA
]V><gZ
//获得文件长度 ''v_8sv
public long getFileSize() h9g5W'.#
{ :%!=Ej.J
int nFileLength = -1; {lx^57v
try{ Vk{0)W7
URL url = new URL(siteInfoBean.getSSiteURL()); v\$XhOK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |p.mA-81
httpConnection.setRequestProperty("User-Agent","NetFox"); cg$7`/U
TX*s T
}SUe 4r&4}
int responseCode=httpConnection.getResponseCode(); ~`8`kk8
if(responseCode>=400) r|?2@VE
{ +#'exgGU^[
processErrorCode(responseCode); 8%vk"h:u:
return -2; //-2 represent access is error 6i{W=$RQ
} "1h|1'S50?
[8O`VSV3
!{r Gt`y
String sHeader; rs 7R5 F
ExY ~.
}g>&l.2X
for(int i=1;;i++) :N%]<Mq
{ \u",bMQF
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); vIz~B2%x
//Utility.log(in.readLine()); l,,5OZw
sHeader=httpConnection.getHeaderFieldKey(i); olQ;XTa01F
if(sHeader!=null) m:X;dcq'3
{ /38^N|/Zr
if(sHeader.equals("Content-Length")) M)Ogb'@#
{ ?ry`+nx
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =;^2#UxXA&
break; XZIj' a0d
} +r4^oT[-
} 1_XdL?h#o
else :;)K>g,b
break; FW=oP>f]w
} DkQy.
} 4}fG{Bk
catch(IOException e){e.printStackTrace ();} &YqgMC
catch(Exception e){e.printStackTrace ();} zcP_-q]1
X;ijCZb3b
u@[D*c1!H
Utility.log(nFileLength); b@z/6y!
z9'ME
co@Q
return nFileLength; Fag%#jxI
} h-Ffs
1r|'n aiZ
A;q}SO%b
//保存下载信息（文件指针位置） r5tv9#4]
private void write_nPos() 97'*Xq
{ ^'6!)y#
try{ ZU7,=B=
output = new DataOutputStream(new FileOutputStream(tmpFile)); 56d,Sk)
output.writeInt(nStartPos.length); Rb|\!
for(int i=0;i<nStartPos.length;i++) gtVI>D'(W
{ zF3fpEKe
// output.writeLong(nPos); q%8,@xg
output.writeLong(fileSplitterFetch.nStartPos); .KXpB7:
output.writeLong(fileSplitterFetch.nEndPos); vfcj,1
} *<"xF'C
output.close(); y]+i.8[
} *";,HG?|Iz
catch(IOException e){e.printStackTrace ();} ORyFE:p$
catch(Exception e){e.printStackTrace ();} oCXBek?\
} ?b:l.0m
2u/~#Rt&*
q.g<gu]
//读取保存的下载信息（文件指针位置） ^ejU=0+cN
private void read_nPos() iRBUX`0
{ TB1E1
try{ o} YFDYi
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); oV&AJ=|\
int nCount = input.readInt(); R'uM7,7
nStartPos = new long[nCount]; `Q' 0l},
nEndPos = new long[nCount]; 8^CL:8lI^\
for(int i=0;i<nStartPos.length;i++) aP>%iRk'J!
{ R%"wf
nStartPos = input.readLong(); \|L ~#{a
nEndPos = input.readLong(); wm%9>mA%
} am]$`7R5d
input.close(); Ze~^+ EE
} 2bPrND\P=
catch(IOException e){e.printStackTrace ();} =EA*h_"q9
catch(Exception e){e.printStackTrace ();} hl(M0cxEWP
} N2 wBH+3w
RLu y;z
%oJ_,m_(
private void processErrorCode(int nErrorCode) K@)Hm\*
{ 7hlgm7^
System.err.println("Error Code : " + nErrorCode); 7q&Ru|T33
} \tc4DS
wf)T-]e
O(2)A>}
//停止文件下载 'vq-~y5^#
public void siteStop() (j@3=-%6G
{ U p=J&^.
bStop = true; .DR^<Qy
for(int i=0;i<nStartPos.length;i++) _z4c7_H3
fileSplitterFetch.splitterStop(); ]vo&NE
?W:YS82
b_+dNoB
} 1:h{( %`&
} ~>2@55wElp
//负责部分文件的抓取 1S/KT4
**FileSplitterFetch.java rtd&WkU rD
*/ ZCsL%(
package NetFox; }F=scbpXj
*8{PoD
O~sv^
import java.io.*; | #Z+s-
import java.net.*; 1AiqB Rs
b9b384Q1O
|)`<D
public class FileSplitterFetch extends Thread { o?%1^6&HE
>={?H?C
"|ZC2Zu<
String sURL; //File URL Qk2^p^ T6
long nStartPos; //File Snippet Start Position =8:m:Y&|`G
long nEndPos; //File Snippet End Position LE#ko2#ke
int nThreadID; //Thread's ID #D4gNQg@R
boolean bDownOver = false; //Downing is over D_mdX9-~
boolean bStop = false; //Stop identical ,rkY1w-
FileAccessI fileAccessI = null; //File Access interface 0$Rl78>(
z !2-U
&ig6\&1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |e49F
{ {BB#Bh[
this.sURL = sURL; /BeA-\B
this.nStartPos = nStart; P|c[EUT
this.nEndPos = nEnd; 5A^$!q P
nThreadID = id; G?Fqm@J{XT
fileAccessI = new FileAccessI(sName,nStartPos);//定位 qI (<5Wxl
} ;;|S QX
"`WcE/(
oZVq}}R
public void run() y8~/EyY|^
{ &USKudXmb
while(nStartPos < nEndPos && !bStop) ]nmVT~lBe"
{ l6kqP
?4QX;s7
B+)HDIPa-
try{ b{X,0a{*
URL url = new URL(sURL); z#DgoA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @ ={Hx$zL
httpConnection.setRequestProperty("User-Agent","NetFox"); uB&um*DP
String sProperty = "bytes="+nStartPos+"-"; 0Z{;sW
httpConnection.setRequestProperty("RANGE",sProperty); ]!% p21e
Utility.log(sProperty); CSu}_$wC#
}wY6^JF
]|6)'L&]*s
InputStream input = httpConnection.getInputStream(); Wra$
//logResponseHead(httpConnection); )7`2FLG
,\".|m1o.
o=%pR|
byte[] b = new byte[1024]; yAyq-G"sO
int nRead; a%FM)/oI|T
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g+:Go9k!F
{ V:Z}cfR.7
nStartPos += fileAccessI.write(b,0,nRead); T ?HG}(2
//if(nThreadID == 1) 3$TU2-x;g
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s28t'
} qL;T^ljP
N?Nu'
39!$x[
Utility.log("Thread " + nThreadID + " is over!"); v4$"{W;'
bDownOver = true; f$2DV:wuC
//nPos = fileAccessI.write (b,0,nRead); -G|?Kl
} -%,3qhsd
catch(Exception e){e.printStackTrace ();} wR(>'?
} eI@nskq#
} iL48
e]!`Cl-f80
dX^d\ wX
//打印回应的头信息 $eSSW+8q"
public void logResponseHead(HttpURLConnection con) p)k5Uh"
{ &%=]lP]
for(int i=1;;i++) C)z?-f
{ Sy0-tK4
String header=con.getHeaderFieldKey(i); !yQ%^g`
if(header!=null) ,qz:(Nr
//responseHeaders.put(header,httpConnection.getHeaderField(header)); z&Kh$ $)[
Utility.log(header+" : "+con.getHeaderField(header)); Uv|?@zy#
else r`OC5IoQ
break; HB0DG<c-
} )?$zY5
} s9\N{ar#
1Z_2s2`p
:|z.F+-/
public void splitterStop() E=&":I6O
{ ,bRYqU?#0
bStop = true; ]ME2V
} esk~\!d
OTmw/#ug
C9VtRq
} |e+r|i]
b.#0{*/G
][V@t^
/* =#.qe=
**FileAccess.java VTl\'>(Cl
*//文件访问(定位，写) d cG)ql4d
package NetFox; k+%c8w 9
import java.io.*; \<kQ::o1y
1>'xmp+#
m+=L}[
public class FileAccessI implements Serializable{ Q*W$!ZUT
('oA{,#L
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [;LP6n7v
RandomAccessFile oSavedFile; + :;6kyM6X
long nPos; l<8+>W`_
y.,li<
uMb[0-5
public FileAccessI() throws IOException n?S~(4%
{ "Gc\"'^r
this("",0); fI"OzIJV
} w%uM=YmuT
kj]m@mS[
t+IrQf,P[
public FileAccessI(String sName,long nPos) throws IOException s#4Q?<65u
{ C)(/NGf
oSavedFile = new RandomAccessFile(sName,"rw"); BRF4p:
this.nPos = nPos; 1{$=N2U
oSavedFile.seek(nPos); ]\6*2E{1m
} |gwGCa+
(RafidiH
LLU]KZhtY|
public synchronized int write(byte[] b,int nStart,int nLen) L5n/eg:Q
{ xW+XN`77
int n = -1; :S=!]la0h
try{ %h4|$
oSavedFile.write(b,nStart,nLen); 1pJ?YV
n = nLen; `(&GLv[i^2
} Ox^VU2K;&.
catch(IOException e) 7z9[\]tt
{ K'zBDrkW-x
e.printStackTrace (); (&oT6Ji
} _64<[2
LR%P\~
3fq'<5 ^
return n; T&u25"QOf
} B/gI~e0
5@yBUwMSj
NUM+tg>KM
} ^^kL.C Ym
M6:$ 0(r
Je#vu`.\\
/* sV-UY!
**SiteInfoBean.java XBN,{
*/ y7-daek
package NetFox; )(W%Hmi
Oi$$vjs2
!DZ4C.
public class SiteInfoBean { )g[7XB/w
`(VVb@:o
-|( q9B
private String sSiteURL; //Site's URL ]Ag{#GJ5D
private String sFilePath; //Saved File's Path tN-B`d1
private String sFileName; //Saved File's Name 31{)~8
private int nSplitter; //Count of Splited Downloading File MURHv3
3 , nr*R!
F?hGt]o
public SiteInfoBean() !y7w~UVs
{//nSplitter的缺省值为5 b*dEX%H8sf
//default value of nSplitter is 5 Rkh ^|_<!
this("","","",5); cPg$*,]
} }`D-]/T8.
u!9bhL`
&OP =O*B
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^_XV}&7Q
{ S\W&{+3
sSiteURL= sURL; A=l1_8,`h
sFilePath = sPath; C.Re*;EI,
sFileName = sName; D}L4uz?
this.nSplitter = nSpiltter; 7oFA5T _
zJT,Hv .
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} _VI3b$
15wwu} X
axLO: Q,
public String getSSiteURL() &ZAc3@l[c
{ *D;VZs0O
return sSiteURL; LAPCL&Z
} <G#z;]N
} f+hB
H`Ld,E2ex&
public void setSSiteURL(String value) z+F:_
{ V SUz+W
sSiteURL = value; Eumdv#Qg
} f f_| 3G
{uji7TB
C 8qVYrw
public String getSFilePath() :j(D&?ao
{ n9r3CLb[
return sFilePath; J&jig?t
} Q5pm^X._j
9Qhk~^ngg
a@U0s+V&a0
public void setSFilePath(String value) DU.[Sp
{ e \ rb
sFilePath = value; et0yS%7+?@
} &4-rDR,
&yQM8J~
; #^Jy#)
public String getSFileName() ht@s!5\LK
{ 5,1q%
return sFileName; |? l6S
} ?5#=Mh#
gw`}eA$
%Lwd1'C%
public void setSFileName(String value) w=S7zzL)
{ l\Or.I7n
sFileName = value; Z`lCS o;
} !%_H1jk
U?:<clh
a,U@ !}K
public int getNSplitter() niIjatT
{ @YfCS8 eH
return nSplitter; I+^B]@"
} Fl^}tC
ET7(n0*P}]
KGI0|Z]n~
public void setNSplitter(int nCount) 2o5v{W
{ &]2z)&a
nSplitter = nCount; !B_?_ a
} zu Jl #3YP
} $&|*v1rH
(mJqI)m8
VIxt;yE
/* vQ}'4i8(
**Utility.java "A_WU|
*/ o(/(`/
package NetFox; 6*,8 H&
NgnHo\)
+{j? +4(B
public class Utility { ReCmv/AE
Q\~4J1
e,}]K'!t
public Utility() >_biiW~x:
{ .wD>0Ig
Hize m!
x hFQjV?V
} u|=G#y;3
r'p;Nj.
//线程睡眠 q($lL~Ls
public static void sleep(int nSecond) 8IH&=3
{ Y'n TyH
try{ 9Osjh G
Thread.sleep(nSecond); j}chU'if
} Z3G>DF:$
catch(Exception e) cK>5!2b
{ $.}fL;BzVz
e.printStackTrace (); ^)b*"o
} I'o9.B8%#
} 5( lE$&
1{%EQhNd
//日志 GG\]}UjX
public static void log(String sMsg) n]x4twZ
{ _y)#N<
System.err.println(sMsg); }VE[W
} Um\Nd#=:
kF~}htv.=
~fs{Ff'
public static void log(int sMsg) UUv&X+Y
{ TeQWrms
System.err.println(sMsg); E`>-+~ZUsk
} q+t*3;X.
} `6!l!8 v
6@!<'l%z
W)V"QrFK
/* Iq_cs '
**TestMethod.java !:`QX\Ux
*/ /wI$}X5o~
package NetFox; f6^H Q1SSt
c3!d4mC:
.0#?u1gXsX
public class TestMethod { Yv9(8
FgQd7p
a)4.[+wnRf
public TestMethod() UBi0 /
{ ///xx/weblogic60b2_win.exe j;1X-
try{ Eti;(>"@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,;H)CUe1"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); SwG:?T!"}
SiteFileFetch fileFetch = new SiteFileFetch(bean); Oh~JyrZy
fileFetch.start(); F^&_O*"
} Fc7mAV=
catch(Exception e){e.printStackTrace ();} >I8R[@
c&AA< 6pkv
JpxJZJ
} }!(cm;XA"
?A2#V(4
xg/3*rL
public static void main(String[] args) `K~300-hOb
{ wvcG <sj
new TestMethod(); !V$m!i;
} ^4O1:_|G
} fZ]Y
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