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)); ,`7;S,f
} cD-.thHO
for(int i=0;i<nEndPos.length-1;i++) 8^fkY'x
{ 9N9dQ}[:g
nEndPos = nStartPos[i+1]; {VC4rA
} &9CKI/K:
nEndPos[nEndPos.length-1] = nFileLength; F+;{s(wx
} By=/DVm)=
} qyP|`Pm4
zy(i]6
2 }QD>
//启动子线程 0y$aGAUm
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; sPCp20x:y8
for(int i=0;i<nStartPos.length;i++) >uN`q1?l'
{ \Vis
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &"dT/5}6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), KKm0@Y
nStartPos,nEndPos,i); CroI,=a&,
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gf]biE"k
fileSplitterFetch.start(); ^(ks^<}
} VjU;[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =RR225
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); )!1; =
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", J@ x%TA
nEndPos = " + nFileLength); _C9*M6IU
// fileSplitterFetch[nPos.length-1].start(); 3F,$}r#
e&dE>m
{mPaloA
//等待子线程结束 }?,Gn]]
//int count = 0; IAt;?4
//是否结束while循环 Cc:4n1|]>
boolean breakWhile = false; q #f U*
/^~3Ib8Fw+
lAsDdxB`
while(!bStop) +w Oa
{ ,63hO.4M
write_nPos(); t&UPU&tY
Utility.sleep(500); 7<Fp3N 3
breakWhile = true; pv2_A
DXlP(={*
E3gR%t
for(int i=0;i<nStartPos.length;i++) gWp\?La
{ +zxj-diM
if(!fileSplitterFetch.bDownOver) q!#e2Dx
{ 2Mc/ah
breakWhile = false; Sf>R7.lpP
break; ?PNG@OK
} !Gu,X'#Ab
} u49zc9
if(breakWhile) tE0DST/
break; &x{CC@g/
nu,#y"WQ
qO=_i d
//count++; #5GIO
//if(count>4) (: IUg
// siteStop(); ]%IcUd}
} :ho)3kB
UhCE.# U
eR r.j
System.err.println("文件下载结束！"); jR@j+p^e
} X>mY`$!/
catch(Exception e){e.printStackTrace ();} R}F0_.
} !RLg[_'
hkw;W[ZWa
G l+[|?N
//获得文件长度 .$+]N[-=
public long getFileSize() ZCi~4&Z#
{ I]P'wav~O
int nFileLength = -1; E6n3[Z
try{ u-Pa:wm0-
URL url = new URL(siteInfoBean.getSSiteURL()); o.t$hv|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |pJ)w
httpConnection.setRequestProperty("User-Agent","NetFox"); qG7^XO Ws-
.lfKS!m2
ud K)F$7
int responseCode=httpConnection.getResponseCode(); IM&2SSmYNH
if(responseCode>=400) 3vPb}
{ $:"r$7
processErrorCode(responseCode); v_f8zk
return -2; //-2 represent access is error gB@Xi*
} 2"lDKjj
FjIS:9^)t5
<=8REA?
String sHeader; 6k;__@B,
*vFVXJo
FblwQ-D
for(int i=1;;i++) /_E8'qlx
{ LZm6\x
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @sJ[<V
//Utility.log(in.readLine()); Pw/Z;N;:V
sHeader=httpConnection.getHeaderFieldKey(i); UKp- *YukT
if(sHeader!=null) Y-6 ?x
{ {J q[N}
if(sHeader.equals("Content-Length")) !b0'd'xe
{ 7''l\3mIn
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); kH1hsDe|&y
break; 3o%,8l,
} YQOdwcLG
} %3scz)4$
else R0y={\*B5k
break; 2bxkZS]
} 'EJ8)2
} O[f*!
catch(IOException e){e.printStackTrace ();} Ed,`1+
catch(Exception e){e.printStackTrace ();} f7 V36Q8
ZzLmsTtzIu
uZ( I|N$
Utility.log(nFileLength); L+Yn}"gIs
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Qj~m;F!
return nFileLength; mdvooJ
} 8RWfv}:X
GwxxW
')t :!#
//保存下载信息（文件指针位置） #}L75
private void write_nPos() 6 ]W!>jDc
{ |n=m{JX\m
try{ ![3#([>4>
output = new DataOutputStream(new FileOutputStream(tmpFile)); :#58m0YLA:
output.writeInt(nStartPos.length); V{;!vt~
for(int i=0;i<nStartPos.length;i++) \y^Od7F
{ F+Rtoq|
// output.writeLong(nPos); I&]d6,
output.writeLong(fileSplitterFetch.nStartPos); HXhz|s0
output.writeLong(fileSplitterFetch.nEndPos); QlJ cj+_h
} h`dtcJ0
output.close(); {8UYu2t
} *"` dO9Yf_
catch(IOException e){e.printStackTrace ();} qLBXyQ;U
catch(Exception e){e.printStackTrace ();} Y~Y-L<`I
} #pP4\n-~hU
F<q'ivj:w
m\`dLrPX4j
//读取保存的下载信息（文件指针位置） Twyx(~'&R
private void read_nPos() R/r)l<X@
{ pC l[DE
try{ k@U8K(:x
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /e :V44
int nCount = input.readInt(); >f#P(
nStartPos = new long[nCount]; D].!u{##
nEndPos = new long[nCount]; T:q_1W?h]
for(int i=0;i<nStartPos.length;i++) YO7Y1(`
{ Wr Ht
nStartPos = input.readLong(); BDSZ'
nEndPos = input.readLong(); }#'wy
} Kk1591'
input.close(); /^^t>L
} XL@i/5C[
catch(IOException e){e.printStackTrace ();} Aifc0P-H
catch(Exception e){e.printStackTrace ();} \Km!#:
} e5KsKzu a
3ny>5A!;2
}S51yDVG_
private void processErrorCode(int nErrorCode) ]|62l+
{ bVmHUcR0
System.err.println("Error Code : " + nErrorCode); [G2@[CtY1
} S[,!
z(2pl}
OJiW@Z_\
//停止文件下载 RY'f%c
public void siteStop() _@9[c9bO
{ A^:[+PJHN
bStop = true; E^w2IIw
for(int i=0;i<nStartPos.length;i++) F8M&.TE_3
fileSplitterFetch.splitterStop(); y\Kr@;q0w
CsHHJgx
r_nB-\
} OV3l)73?t
} v+uq
//负责部分文件的抓取 i^Vb42%y
**FileSplitterFetch.java M#X8Rs1`
*/ "s!!\/^9C
package NetFox; 52?zBl`|
twElLOE
-V0_%Smc
import java.io.*; HA&7 ybl
import java.net.*; Jb~$Vrdy
Z-|.j^n
0JzH dz
public class FileSplitterFetch extends Thread { Oxs O
.[&0FHnJ5
!z">aIj\6
String sURL; //File URL G2 A#&86J{
long nStartPos; //File Snippet Start Position _DsA<SJ]
long nEndPos; //File Snippet End Position YoyJnl.?u
int nThreadID; //Thread's ID m;-FP 2~
boolean bDownOver = false; //Downing is over h}-}!v
boolean bStop = false; //Stop identical `G*7y7
FileAccessI fileAccessI = null; //File Access interface zQ3m@x
+GCN63nX
;6S,|rC]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException XN9s!5A<L)
{ Y~\71QE>
this.sURL = sURL; su;u_rc,
this.nStartPos = nStart; R<.<wQ4I
this.nEndPos = nEnd; 2%|
nThreadID = id; Aq'yr,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 zh`!x{Z?^
} 8:=&=9%
6. N?=R
"fK`F/
public void run() YXCltME
{ np2oXg%
while(nStartPos < nEndPos && !bStop) e RY2.!
{ aT}Mn(F*?
^X-3YhJ4U
,/0Q($oz
try{ rR`'l=,t
URL url = new URL(sURL); \kSoDY`l&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GL;@heP
httpConnection.setRequestProperty("User-Agent","NetFox"); y/=:F=H@w
String sProperty = "bytes="+nStartPos+"-"; :})(@.H
httpConnection.setRequestProperty("RANGE",sProperty); Z]?Tx2|7
Utility.log(sProperty); N(i%Oxp1
q#LB 2M
>[t0a"
InputStream input = httpConnection.getInputStream(); ZK:dhwer
//logResponseHead(httpConnection); W0e+yIaR
g4b-~1[S
?LJ$:u
byte[] b = new byte[1024]; ycYT1Sg8
int nRead; 2iOn\ ^]x
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1ocd$)B|}
{ VB>KT(n-b
nStartPos += fileAccessI.write(b,0,nRead); Q{%2Npvq
//if(nThreadID == 1) dRwOt
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @z $,KUH
} (w4w
y8} fj=
7$3R}=Z`\q
Utility.log("Thread " + nThreadID + " is over!"); S1jI8 #z}_
bDownOver = true; =5:L#` .
//nPos = fileAccessI.write (b,0,nRead); z4t.-9(C
} $t*>A+J
catch(Exception e){e.printStackTrace ();} |-Rg].
} =$bJ`GpJ
} fP 1V1ao
vTnrSNdSE
Pdgn9
//打印回应的头信息 3a9%djGq
public void logResponseHead(HttpURLConnection con) 5)712b(&
{ rP4v_?Zg+
for(int i=1;;i++) nW)-bAV<
{ =^liong0
String header=con.getHeaderFieldKey(i); lMkDLobos
if(header!=null) .CJQ]ECl7p
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Xae0xs
Utility.log(header+" : "+con.getHeaderField(header)); qHwHP 1
else 'ec G:B`S
break; (!b_o A8V
} E :gS*tsY
} w+A:]SU
Skb,cKU
5L ]TV\\
public void splitterStop() 'XW[uK]w)
{ >?Y)evW
bStop = true; 05sWN0
} t<~WDI|AN
y{&k`H
:~uvxiF
} Yz<,`w5/6~
V+\L@mz;
nP]tc
/* Q?"o.T';
**FileAccess.java IZ){xI
*//文件访问(定位，写) JFOto,6L:
package NetFox; :TU|;(p
import java.io.*; #+VH]7]
yf|,/{S
G.j R
public class FileAccessI implements Serializable{ g/*x;d=
m(2(Caz{
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /"~ D(bw0=
RandomAccessFile oSavedFile; GCrIaZ
long nPos; 1zo0/<dk
3C:!\R
^3>Qf
public FileAccessI() throws IOException XOOWrK7O
{ NxOiT#YH
this("",0); euxkw]`h6
} hbZ]DRg
Qu 7#^%=
)gX7qQ
public FileAccessI(String sName,long nPos) throws IOException z@70{*
{ 4}i2j
oSavedFile = new RandomAccessFile(sName,"rw"); SW94(4qo
this.nPos = nPos; LwPZRE#
oSavedFile.seek(nPos); fj 14'T
} [_$r-FA
,(1n(FZ
l ~bjNhk
public synchronized int write(byte[] b,int nStart,int nLen) )7X+T'?%
{ B: '}SA{
int n = -1; ~Onj|w7
try{ 72i]`
oSavedFile.write(b,nStart,nLen); -|1H-[Y(
n = nLen; w@K4u{|
} f+}Rj0A
catch(IOException e) ;HKb
{ 4blw9x N
e.printStackTrace (); It5U=PU
} M lv
iTX:*$~I
1\'?.
return n; R1!F mZW8
} ;f]p`!] 3
^A&i$RRO
jwP}{mi*
} {"^LUw8fd
q+j.)e
g]fdsZv
/* uq/z.m
**SiteInfoBean.java m7dpr$J
*/ `5HFRgL`.
package NetFox; 0n FEPMO
^Vbx9UN/
!b !C+ \v
public class SiteInfoBean { qcNu9Ih
Ou26QoT9XI
i146@<\G{P
private String sSiteURL; //Site's URL L9lNAiOH
private String sFilePath; //Saved File's Path |*G$ilu
private String sFileName; //Saved File's Name dz3KBiq
private int nSplitter; //Count of Splited Downloading File xH,D bAC;
2&e2/KEWR
RFsd/K;Zp
public SiteInfoBean() [RAzKzC\M
{//nSplitter的缺省值为5 Fi7G S;
//default value of nSplitter is 5 'zRi;:UHA
this("","","",5); $ 8"we
} a\K__NCrX
jY~W*
Z.4 vKO[<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) a&sVcsX
{ "wPA;4VQ
sSiteURL= sURL; miWPLnw=L
sFilePath = sPath; :,<G6"i
sFileName = sName; sIM^e
this.nSplitter = nSpiltter; S!LLC{
|b BA0.yS
4qd =]i
} )td?t.4
|UudP?E
$0kuR!U.N
public String getSSiteURL() qdM=}lbc
{ gs xT
return sSiteURL; Q3@MRR^tY
} X0QY:?
!!{!T;)l
f1Z
public void setSSiteURL(String value) LTn@OhC
{ %^`b)
sSiteURL = value; ^~p^N <
} {6y@;Fd
@;6I94Bp
3Y;<Q>roT
public String getSFilePath() 9_$i.@L1
{ T%[&[8{8
return sFilePath; yLC5S3^1\"
} bOB<m4
1WTDF
eX{:&Do
public void setSFilePath(String value) B4&K2;fg_
{ tRUGgf`
sFilePath = value; ?(t{VdZSzQ
} t PJW|wo
H3}eFl=i2
hJ)\Vo
public String getSFileName() 7EfLd+
{ JU6PBY~C'
return sFileName; {vp|f~}zTw
} A`#/:O4|f
7Gos-_s
b0PQ;?R#V
public void setSFileName(String value) wt@Qjbqd8
{ %',bCd{QW
sFileName = value; A"Prgf eT
} Fm{/&U^
4s:S_Dw
@|=JXSr!KY
public int getNSplitter() X\=m
{ ]-rhc.Gk@1
return nSplitter; ,k9@%{4 l
} EMTAl;P
MV(Sb:RZ
vqeWt[W v
public void setNSplitter(int nCount) XEUy,>mR
{ S-5|t]LV
nSplitter = nCount; $ ]fautQlt
} F0D7+-9[
} J{69iQ
Yn~N;VUA
RaT_5PH~g
/* hja;d1yH
**Utility.java kPuI'EPK
*/ ~Z{IdE
package NetFox; ( !THd
'Nqa=_<WW
E7CeE6U
public class Utility { I6.!0.G
(V06cb*42[
7\T~KYb?
public Utility() hx5oTJR
{ YKWiZ
z{>p<)h
9B&fEmgEc?
} 3IlflXb
en5sqKqh+
//线程睡眠 >RTmfV
public static void sleep(int nSecond) l>kREfHq!{
{ v/s6!3pnl
try{ b3vPGR
Thread.sleep(nSecond); fOHgz,x=
} j "^V?e5
catch(Exception e) 2!Gb4V
{ NI%&Xhn!*>
e.printStackTrace (); Cj +{%^#
} H}p5qW.tH:
} &Q>tV+*
k^%Kw(/
//日志 fqY;>Z
public static void log(String sMsg) `w;8xD(
{ 1Z$` }a
System.err.println(sMsg); 8M~^/Zc
} }~akVh`3
ov9+6'zya
VJf|r#2
public static void log(int sMsg) Uc[@]
{ ?x\tE]
System.err.println(sMsg); 8NUVHcB6
} d41DcgG'j(
} m4r!Ck|
qb[UA5S\`
2C&G'@>
/* AWG;G+
**TestMethod.java O'i!}$=g
*/ -,Oq=w*EV
package NetFox; U?[_ d
J?1U'/Wx2
"J_#6q*
public class TestMethod { p!_3j^"{
xIlo@W6
1[4)Sq?
public TestMethod() q; n
{ ///xx/weblogic60b2_win.exe g2|qGfl{C
try{ kgl7l?|O
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &| guPZ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); A#@9|3
SiteFileFetch fileFetch = new SiteFileFetch(bean); Pc:5*H
fileFetch.start(); qx;8Hq(E[
} )[]*Y]vSx
catch(Exception e){e.printStackTrace ();} `alQmGUZ
..=WG@>$+
c(j|xQ\pE
} 2x<A7l)6
937 z*mh
Ht,dMt>:
public static void main(String[] args) hh1 ?/
{ |l#<vw wE
new TestMethod(); \$B%TY
} yd>b2 M
} +!F+mV9
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