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:fY
} a&.8*|w3
for(int i=0;i<nEndPos.length-1;i++) 35B0L.R
{ 5z5#_*)O
nEndPos = nStartPos[i+1]; 2o6KVQ
} ^Ml)g=Fq
nEndPos[nEndPos.length-1] = nFileLength; 1q}iUnR
} fg*IHha
} p r(:99~3
B3c rms['
Cbx/
//启动子线程 *S:^3{.m=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \[B5j0vV,
for(int i=0;i<nStartPos.length;i++) &P&M6v+
{ Zh{Pzyp
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 80![aj}z4G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -%5*c61
nStartPos,nEndPos,i); Br`Xw^S
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &h`s:Y
fileSplitterFetch.start(); #=OKY@z/
} (05/}PhB`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2%. A{!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); pu0IhDMn
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3-lJ]7OT
nEndPos = " + nFileLength); }_@*,
// fileSplitterFetch[nPos.length-1].start(); 9=ns.r
Xb?P'nD
?`uY*+u
//等待子线程结束 {tOu+zy
//int count = 0; R',Q)<
//是否结束while循环 ,=Xr'7w,
boolean breakWhile = false; QPg QM6
O:{I9V-=>s
|XtN\9V.
while(!bStop) !X` 5
{ c/^} =t(
write_nPos(); #i%it
Utility.sleep(500); CDK0 $W n
breakWhile = true; ?y>P
vYKKv%LE
1}Tbp_
for(int i=0;i<nStartPos.length;i++) +Hc[5WL
{ !)?n n3
if(!fileSplitterFetch.bDownOver) !0zbWB9
{ l"W9uS;\T
breakWhile = false; }/4 AT
break; E<:XHjm
} ?k TVC
} }cn46L%/
if(breakWhile) VY<$~9a&1
break; 58DkVQ6
FWq+'GkSV
WJ<nc+/v:
//count++; M56^p,
//if(count>4) 2RFYnDN
// siteStop(); ylUxK{
} IX$dDwY|O>
p^3]Q
-=H*(M
System.err.println("文件下载结束！"); yS[:C 2v
} 0BMKwZg
catch(Exception e){e.printStackTrace ();} 47|Lk]+O
} n;@PaE^8=
s )POtJ<
+0{m(%i
//获得文件长度 6NPCp/
public long getFileSize() MCZTeYnx
{ EcxPbRg
int nFileLength = -1; <1YINkRz
try{ (0/,R
URL url = new URL(siteInfoBean.getSSiteURL()); umaF}}-Q{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); '-oS=OrZ
httpConnection.setRequestProperty("User-Agent","NetFox"); :.e`w#$7
|]1-ck!
9]<p
int responseCode=httpConnection.getResponseCode(); i,r O3Jn
if(responseCode>=400) z#ab V1 Xi
{ VCSHq&p8
processErrorCode(responseCode); {F6>XuS=u
return -2; //-2 represent access is error twv|,kM
} 48hu=,)81*
=iW!Mq
Ebw1 %W KC
String sHeader; $N'AZY]4]
cXU8}>qY7
w#vSZbh
for(int i=1;;i++) Uy2NZ%rnt
{ "(zvI>A
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )h6hN"#V5
//Utility.log(in.readLine()); gHdNqOy c
sHeader=httpConnection.getHeaderFieldKey(i); Px{Cvc
if(sHeader!=null) e/Wrm^]y
{ VT8PV5z
if(sHeader.equals("Content-Length")) jd8`D6|Z
{ gqV66xmJ3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *oopdGue
break; B>Tfyo
} UF0W%Z
} O=~8+sa
else ZKy)F-yX
break; s~ ||Vv!
} cyrVz4_a
} d` %8qLIW
catch(IOException e){e.printStackTrace ();} ^0)Mc"&{
catch(Exception e){e.printStackTrace ();} r<VZEbm)
Oxo?\ :T
#hG0{_d7
Utility.log(nFileLength); C))5,aX
h DpIwzJ
7=i8$v&GX
return nFileLength; YXz*B5R
} 2;Vss<hR4A
~e*3_l>9
-FQ!
//保存下载信息（文件指针位置） hgIqr^N9
private void write_nPos() H'KCIqo
{ kt`_n+G
try{ BIGln`;,f
output = new DataOutputStream(new FileOutputStream(tmpFile)); EQ 'L"
output.writeInt(nStartPos.length); )4:K@
for(int i=0;i<nStartPos.length;i++) Loz5[L
{ =1Nz* c
// output.writeLong(nPos); aF*KY<w
output.writeLong(fileSplitterFetch.nStartPos); sB!#`kh
output.writeLong(fileSplitterFetch.nEndPos); ?YE'J~0A6
} -#<6
output.close(); T8<pb^#
} .5L|(B=H
catch(IOException e){e.printStackTrace ();} #&zM.O1Q
catch(Exception e){e.printStackTrace ();} Yc~(Wue
} tfB}U.
(-S<9u-r
mm}y/dO~}
//读取保存的下载信息（文件指针位置） O2i7w1t
private void read_nPos() gJa48 pi
{ #b~B 0:U
try{ -55[3=#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _y>mmE
int nCount = input.readInt(); SeuC7!q{
nStartPos = new long[nCount]; +cH,2^&
nEndPos = new long[nCount]; :j(e+A1@
for(int i=0;i<nStartPos.length;i++) R[_Q}W'HG
{ jfmHc(fX4
nStartPos = input.readLong(); a ?D]]0%
nEndPos = input.readLong(); zT<fTFJ1
} I=aoP}_
input.close(); 42/MBP`\Y
} TF]bmM})0
catch(IOException e){e.printStackTrace ();} *JnY0xP
catch(Exception e){e.printStackTrace ();} l5h+:^#M5c
} X,5}i5'!
Z2n Jw
k+9*7y8w
private void processErrorCode(int nErrorCode) *Bfo"["0.
{ G5WQTMzf&
System.err.println("Error Code : " + nErrorCode); `iHyGfm
} 8^IV`P~2M
zM+4<k_dH]
LZ#=Ks
//停止文件下载 pbCj ^
public void siteStop() {6 #Qm7s-
{ j1zrjhXI
bStop = true; jY;T:C-T
for(int i=0;i<nStartPos.length;i++) ;X_bDiG$
fileSplitterFetch.splitterStop(); I+oe{#:.
[8C|v61Y
m}UcF oaO
} T`?7z+2A
} o*MiKgQ&
//负责部分文件的抓取 Xr:gm`[
**FileSplitterFetch.java u+/Uc:XK)
*/ {c :7:
package NetFox; ]& 8c 45c
~];r{IU
rn$G.SMgz
import java.io.*; Cn"_x
import java.net.*; y^!>'cdV
YD3jP}Ym
yj$$k~@
public class FileSplitterFetch extends Thread { GB%kxtGD;\
,NO2{Ha$
qt(+X
String sURL; //File URL Hs:0j$
long nStartPos; //File Snippet Start Position 1d$qr`
long nEndPos; //File Snippet End Position t1JU_P
int nThreadID; //Thread's ID sX@}4[)<&
boolean bDownOver = false; //Downing is over ^ps6\>=0cW
boolean bStop = false; //Stop identical &Fiesi!tET
FileAccessI fileAccessI = null; //File Access interface W [*Go
4,,DA2^!
%p48=|+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _sb~eB~<(
{ 0g2?
this.sURL = sURL; Iuyq!R4:7
this.nStartPos = nStart; ZUyS+60
this.nEndPos = nEnd; m?<^b_a}
nThreadID = id; ~8 B]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 f+cN'jH E
} -uKTEG[
Ypx5:gm|J
y Nc@K|
public void run() z''ejq
{ j.&Y'C7GOC
while(nStartPos < nEndPos && !bStop) o%b6"_~%3
{ /78zs-
;J@U){R
KqN;a i,F
try{ 4U8N7
URL url = new URL(sURL); uTdx`>M,O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GE8.{P
httpConnection.setRequestProperty("User-Agent","NetFox"); u`.3\Geh
String sProperty = "bytes="+nStartPos+"-"; o)bKs>` U
httpConnection.setRequestProperty("RANGE",sProperty); SK5_^4
Utility.log(sProperty); r6eZ-V`4
<{+U- ^rzR
w%?Zb[!&
InputStream input = httpConnection.getInputStream(); 5tI#UBha
//logResponseHead(httpConnection); zfD@/kU
&cWC&Ws"
{wDq*va
byte[] b = new byte[1024]; +/[L-&,
int nRead; bUsX~R-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *rgF[ :
{ y6dQ4Whv&
nStartPos += fileAccessI.write(b,0,nRead); -Qn l)JB
//if(nThreadID == 1) 4VHWoN"U
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VFrp7;z43
} VA>0Y
p,V%wGM
3(Ns1/;?,
Utility.log("Thread " + nThreadID + " is over!"); )oALB vX
bDownOver = true; 5hHLC7tT9
//nPos = fileAccessI.write (b,0,nRead); 3ey.r%n
} .=)[S5.BVq
catch(Exception e){e.printStackTrace ();} abAw#XQ8
} RWRqu }a
} 1V wcJd
W ]$/qyc&J
.Y|wG<E
//打印回应的头信息 <PFF\NE9
public void logResponseHead(HttpURLConnection con) q;lR|NOh
{ (rc7Cp3
for(int i=1;;i++) 8(Q|[
{ [_KV;qS%/
String header=con.getHeaderFieldKey(i); S n<X
if(header!=null) m68>`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B^!-%_q
Utility.log(header+" : "+con.getHeaderField(header)); -e_|^T"
else QH,Fw$1
break; m2H?VY.^K
} y^e3Gyk
} J)^F
9[`c"Pd
Lu~E5 ,
public void splitterStop() ^9`|QF
{ joDqv,iW8
bStop = true; `M*jrkM]x
} op@=0d??
yM}3u4FG
KYZ#.f@
} @tJ4^<`P{
')}itS8
,J'_Vi
/* .hM t:BMf*
**FileAccess.java E]v]fy"
*//文件访问(定位，写) /N({"G'
package NetFox; !g`I*ZE+e
import java.io.*; w=CzPNRHH!
p>O/H1US;
<@# g2b
public class FileAccessI implements Serializable{ Y]=k"]:%
oB%_yy+
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &qK:LHhj
RandomAccessFile oSavedFile; : h(Z\D_
long nPos; F\hVunPVx
6yBd9=3K
Z^}[CQ&Am
public FileAccessI() throws IOException pH2/."zE<
{ }a/z.&x]V
this("",0); 'Hzc"<2Y\
} $hHV Ie]+
*Ojl@N
piH0_7qr
public FileAccessI(String sName,long nPos) throws IOException Q)y5'u qZ
{ mo3A*|U
oSavedFile = new RandomAccessFile(sName,"rw"); m?; ?I]`
this.nPos = nPos; sYo&@~T
oSavedFile.seek(nPos); 7AS_Aw1L
} 1hlU 6=Y
MRw4?HqB
?:M4GY"gV
public synchronized int write(byte[] b,int nStart,int nLen) :h |]j[2p
{ |V4<eF-0S
int n = -1; $.t>* Bq
try{ mBJr*_p
oSavedFile.write(b,nStart,nLen); D)pTE?@W'
n = nLen; >_xuXEslUz
} YF-A8gXS
catch(IOException e) TpwN2 =
{ 7R7+jL,
e.printStackTrace (); 3u/AqL
} !yVY[
dA (n,@{
6-uLK'E
return n; -%]1q#C>@
} rQ_]%ies8
PqL.^
jVLJqWP'!
} Xz)qtDN|(
j#2EQ
u]7wd3(
/* a??8)=0|}
**SiteInfoBean.java !V(r p80
*/ s*_fRf:
package NetFox; 1og+(m`BL
G&Dl($
|`Noj+T47I
public class SiteInfoBean { (hdu+^Qj=
SASLeGaV
jI0gf&v8
private String sSiteURL; //Site's URL 'e' p`*
private String sFilePath; //Saved File's Path 7i{(,:
private String sFileName; //Saved File's Name *Ow2,{Nn
private int nSplitter; //Count of Splited Downloading File W;cYg.W2
79cM_O
Ncsh{.
public SiteInfoBean() ;9WUt,R
{//nSplitter的缺省值为5 W7b m}JHn
//default value of nSplitter is 5 },#7
this("","","",5); p}h.2)PO
} :\qapFV
+&S6se4
x~R,rb
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) I#M>b:"te
{ j)Ak:l%a
sSiteURL= sURL; 4bp})>}jB
sFilePath = sPath; '2i !RT-
sFileName = sName; rm9>gKN;#
this.nSplitter = nSpiltter; q^sZP\i,*;
,c^nW
"OK[uug
} R3U|{vgl
#T2J +
1%*\*z
public String getSSiteURL() 7(X z%v
{ GM'yOJo
return sSiteURL; '7PaJj=Nx
} G"E_4YkJ
>;hAw!|#
i>,AnkI&
public void setSSiteURL(String value) T}=^D=
{ :>;F4gGVG
sSiteURL = value; r~h#
} JffaT_"\
xlJWCA*>
M /v@C*c
public String getSFilePath() !rr,(!Ip?O
{ hL6;n*S=
return sFilePath; ~gff{Nzk
} Tn1V+)
}.E^_`
,0,FzxX0!
public void setSFilePath(String value) YfB)TK\W9/
{ 'UWkJ2:!
sFilePath = value; cPuXye
} [bP^RY:
`MuX/[q
ls:oC},p*
public String getSFileName() ]q{_i
{ bI|G %
return sFileName; o}114X4q;
} )]FXUz|;
&`v?oN9$
UAhWJ$(C
public void setSFileName(String value) kl.;E{PL
{ ;]Q6K9.d8
sFileName = value; bV&9>fC
} (~zu4^9w
2<I=xWwFA
f%@~|:G:
public int getNSplitter() =dDPQZEin
{ `sT;\
return nSplitter; lMGO4U[z
} m","m
jL^@;"/XhC
czD"mI!
public void setNSplitter(int nCount) {<gv1Yht
{ >x;\H(g
nSplitter = nCount; aF^NYe
} 94ruQ/
} $$NWN?H~
~>u|7M$(
7GsKD=bl]
/* ApeqbD5g&
**Utility.java IoLi7NKw
*/ s__xBY
package NetFox; "d$~}=a[
;un@E:
z80P5^9
public class Utility { bc'IoD/
=b:XL#VA
EwN{|34C
public Utility() MVzuE}
{ f1ANziC;i
GT<oYrjU
<z,)4z++
} ==m[t- 9x
F/5G~17
//线程睡眠 Mg`!tFe3
public static void sleep(int nSecond) Dc-K08c
{ z eT`kZ
try{ fF0i^E<
Thread.sleep(nSecond); T3zovnR
} ]5f;Kz)
catch(Exception e) {V QGfN
{ OLb s~ >VA
e.printStackTrace (); ?yef?JI$p
} r9_ ON|
} mEd2f^R
8eS(gKD
//日志 Fk/I (Q
public static void log(String sMsg) ZgxB7zl//
{ tjx8UgSi
System.err.println(sMsg); 3?*dv14
} 2 3PRb<q
-|m3=#
+zMPkbP6
public static void log(int sMsg) #!R>`l(S
{ }b(hD|e
System.err.println(sMsg); cr!W5+r
} Jh EC
} iX+8!>Q
JKM(fX+
+ausm!~6
/* I </P_:4G
**TestMethod.java f $Agcy
*/ "i;.>
package NetFox; sq_>^z3T
c]|vg=W
n;Oe-+oSC
public class TestMethod { 7<^+)DsS?
2L4[~>
]H n:c'aT
public TestMethod() DPzW,aIgv
{ ///xx/weblogic60b2_win.exe )sm9%|.&
try{ hc|A:v)]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); NlEyT9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~{Iw[,MJ
SiteFileFetch fileFetch = new SiteFileFetch(bean); ZR}v_]l^
fileFetch.start(); eA!Z7 '
} .A< HM}
catch(Exception e){e.printStackTrace ();} '\#q7YjaL
IEy$2f>Ns
YP02/*'
} aA|{r/.10K
%[p*6&V
`}),wBq
public static void main(String[] args) zVS{X=u
{ g9pKoi|\E
new TestMethod(); <\^o
} crIF5^3Yby
} 9xK>fM&u
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