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)); T}Ve:S
} &Yd6w}8
for(int i=0;i<nEndPos.length-1;i++) vg*~t3{L
{ 9rgvwko
nEndPos = nStartPos[i+1]; y`J8hawp
} 5a2+6N
nEndPos[nEndPos.length-1] = nFileLength; E>bpq^;r
} h<bCm`qj
} .FA99|:
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yhd]s0(!
//启动子线程 R#HX}[Hb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; B9S@G{`
for(int i=0;i<nStartPos.length;i++) \qtdbi|Y
{ t/h,-x
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wnHfjF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;1q|SmF
nStartPos,nEndPos,i); (9v%66y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); NF'<8{~
fileSplitterFetch.start(); &A~hM[-
} Dfy=$:Q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RhkTN'vO
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \W7pSV-U
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", DC2[g9S>8@
nEndPos = " + nFileLength); B{>x
// fileSplitterFetch[nPos.length-1].start(); !HKW_m^3J
lg*?w/JX+
L)"CE].
//等待子线程结束 a7jE*%f9
//int count = 0; sCE%./h]
//是否结束while循环 {TaYkuWS
boolean breakWhile = false; nBwDq^
3zMaHh)mj
)C0d*T0i
while(!bStop) J>1%*Tz
{ O"J"H2}S
write_nPos(); ^ LVKXr
Utility.sleep(500); Bv#?.0Ez;
breakWhile = true; huvn_
rTim1<IXR
H{1'- wB
for(int i=0;i<nStartPos.length;i++) _}tPtHPa/
{ n_kE
if(!fileSplitterFetch.bDownOver) '1X^@]+6
{ ,>Dpt<
breakWhile = false; }H|'W[Q.
break; |qpFR)l
} RV%)~S@!R
} vb3hDy
if(breakWhile) 8WC_CAP
break; 0bteI*L
ZtY?X- 4_
~Gl5O`w(
//count++; d '\^S}
//if(count>4) 0 gR_1~3
// siteStop(); S}qGf%
} rA}mp]
k+~2 vmS
(,b\"Q
System.err.println("文件下载结束！"); p!K^Q3kO
} B_>r|^Vh
catch(Exception e){e.printStackTrace ();} `W.g1"o8W4
} QWE\Ud.q
p$cb&NNh*H
i!iG7X)qT
//获得文件长度 "bz]5c~
public long getFileSize() c-U]3`;Q
{ e@iz`~[
int nFileLength = -1; V>c !V9w
try{ J+}z*/)|#
URL url = new URL(siteInfoBean.getSSiteURL()); oWEzzMRz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m]c1DvQb
httpConnection.setRequestProperty("User-Agent","NetFox"); ()5X<=i
H~bbkql
.@$A~/ YU
int responseCode=httpConnection.getResponseCode(); 6W:FT Pt44
if(responseCode>=400) j1=su~
{ m[Mw2F
processErrorCode(responseCode); G!lF5;Ad`
return -2; //-2 represent access is error pl/ek0QX
} ]}n|5
ZO>)GR2S
[}l#cG6 k
String sHeader; t*`Sme]"B
eKf5orN
u#NX`_
for(int i=1;;i++) 4j(`koX_
{ WJMmt XO
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); p3e=~{v*
//Utility.log(in.readLine()); ^tIYr<I
sHeader=httpConnection.getHeaderFieldKey(i); 4/OmgBo'
if(sHeader!=null) tlB-s;
{ n%Oq"`w4
if(sHeader.equals("Content-Length")) Q{CRy-ha
{ ppGWh
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); @FF80U4'
break; `qRyh}Ax"
} _-2ntO<E
} 5&xbGEP$
else M{SJ8+G
break; ]dgi]R|`
} + WT?p]
} VCwC$ts
catch(IOException e){e.printStackTrace ();} Yv0y8Vz@
catch(Exception e){e.printStackTrace ();} BCtKxtbS
f?> ?jf
&.qLE
Utility.log(nFileLength); P)LOAe1'
Ihv@2{*(b
mP's4
return nFileLength; BqUwvB4
} , K:d/
tH#t8Tq5x
HMDuP2Y
//保存下载信息（文件指针位置） 6cD3(//
private void write_nPos() ^f9@=I
{ /:"^,i\t
try{ ]c bXI
output = new DataOutputStream(new FileOutputStream(tmpFile)); g:@4/+TSt
output.writeInt(nStartPos.length); F>GPi!O
for(int i=0;i<nStartPos.length;i++) [f}`reRlZ
{ 5.D0 1?k
// output.writeLong(nPos); Pq@-`sw
output.writeLong(fileSplitterFetch.nStartPos); sL;;'S&
output.writeLong(fileSplitterFetch.nEndPos); <[u(il
} GVfRy@7n
output.close(); #Nad1C/]
} VTY #{
catch(IOException e){e.printStackTrace ();} 1.TIUH1
catch(Exception e){e.printStackTrace ();} &Pc.[k
} /1$u|Gs *
7|jy:F,w%
>V4r'9I
//读取保存的下载信息（文件指针位置） f1sp6S0V\
private void read_nPos() I zVc
{ #2"'tHf4
try{ 9+/D\|"{
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); V]m}xZ'?^
int nCount = input.readInt(); s_^N=3Si
nStartPos = new long[nCount]; %@|)&][hO
nEndPos = new long[nCount]; kUfbB#.5L
for(int i=0;i<nStartPos.length;i++) @Ae&1O;Zh
{ YY(_g|;?8
nStartPos = input.readLong(); 9c[bhGD?
nEndPos = input.readLong(); 53d`+an2
} Cl3L)
input.close(); Br.UN~q
} V<?0(esgR
catch(IOException e){e.printStackTrace ();} |WSpWsr,
catch(Exception e){e.printStackTrace ();} RCoDdtMo
} Jd',v
}EP}D?Mmu
ii>^]iT
private void processErrorCode(int nErrorCode) /I{K_G@
{ 8&3&^!I
System.err.println("Error Code : " + nErrorCode); p"- %~%J=
} esq~Ehr=
BOP7@D
RLzqpE<rJ
//停止文件下载 ?P4y$P
public void siteStop() V?mk*CU
{ 4mtO"'|
bStop = true; n_k`L(8*
for(int i=0;i<nStartPos.length;i++) 3Bvz& `\
fileSplitterFetch.splitterStop(); -$_FKny
B-$zioZ
wXZ9@(^
} &9z&#`AY]>
} eu~ u-}.
//负责部分文件的抓取 ~%eE%5!k
**FileSplitterFetch.java O(v>\MV
*/ B9$pG
package NetFox; [_(uz,'
:UAcS^n7h"
/>pAZa
import java.io.*; k\9kOZW
import java.net.*; QDVSFGwr
X.FoX
Bj9FSKiH
public class FileSplitterFetch extends Thread { _HjB'XNr(
SuNc&e#(
33wVP}e5
String sURL; //File URL MPn/"Fij$
long nStartPos; //File Snippet Start Position +$xw0)|
long nEndPos; //File Snippet End Position 7i'clB9!
int nThreadID; //Thread's ID )s4:&!
boolean bDownOver = false; //Downing is over N}<!k#d E
boolean bStop = false; //Stop identical ~4Mz:h^
FileAccessI fileAccessI = null; //File Access interface g0;;+z
|T/s>OW
p$= 3$I
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException S3$C#mHX
{ Om>?"=yDE
this.sURL = sURL; g{uiY|
this.nStartPos = nStart; )EQI>1_
this.nEndPos = nEnd; m-+>h:1b|9
nThreadID = id; 5w{U/v$Z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (FZ8T39
} ?<Hgq8J
b$_qG6)IJO
p@O,-&/D
public void run() z@?y(E
{ }NRt:JC
while(nStartPos < nEndPos && !bStop) qs= i+
{ mwN"Cu4t
m7RyFnR2
.j"heYF)
try{ x\yr~$}(J
URL url = new URL(sURL); ;]=@;? 9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o4@d,uIw^
httpConnection.setRequestProperty("User-Agent","NetFox"); iTs"RW
String sProperty = "bytes="+nStartPos+"-"; :#_k`{WG
httpConnection.setRequestProperty("RANGE",sProperty); i,%N#
Utility.log(sProperty); z4` :n.
$sZ4r>-
Z#[%JUYp'
InputStream input = httpConnection.getInputStream(); +ZGH
//logResponseHead(httpConnection); k6GQH@y!
`[XH=-p
0;,Y_61
byte[] b = new byte[1024]; ;=E}PbZt2
int nRead; a?4Asn
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6 b?K-)kL
{ =CS$c?
nStartPos += fileAccessI.write(b,0,nRead); *f{4_ts
//if(nThreadID == 1) ,KF>@3f
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6 OvH"/X4
} zlTLp-^Y
rg#/kd<?[V
b"`fS`@/MW
Utility.log("Thread " + nThreadID + " is over!"); H@ty'z?
bDownOver = true; M?hPlo"_
//nPos = fileAccessI.write (b,0,nRead); K`ygW|?gt
} LWSy"Cs*
catch(Exception e){e.printStackTrace ();} 3m2y<l<
} dl |$pm@x
} h.Sbds
s|Vs#o.P)
.i*ja*
//打印回应的头信息 NS+uiy
public void logResponseHead(HttpURLConnection con) -em3 #V
{ q$IU!I4
for(int i=1;;i++) M195[]
{ TaKHr$h
String header=con.getHeaderFieldKey(i); .L^;aL
if(header!=null) ^h#A7 g
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +iQ~ Y2Gh
Utility.log(header+" : "+con.getHeaderField(header)); K;s`
else ^L Xr4
break; D62'bFB^
} N"Y%*BkH
} 6& hiW]Adm
7Wiwnv_"
O8rd*+
public void splitterStop() |Xd&aQ
{ sk0/3X*Q%
bStop = true; vp d!|/
} gu'+kw
7)Tix7:9S;
#^ .G^d(=
} `ZP[-:`
t*6C?zEAU
f^5sJ0;%
/* Y2N$&]O{
**FileAccess.java 9c1q:>|
*//文件访问(定位，写) #-R]HLW*
package NetFox; N "eK9>
import java.io.*; vt5>>rl
!y!s/i&P%
5"q{b1
public class FileAccessI implements Serializable{ !VrBoU4<d
!}1l8Y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 y] Cx[
RandomAccessFile oSavedFile; ]#q$i[Y
long nPos; Aqg$q* Y
?9 `T_,
a<+Rw{
public FileAccessI() throws IOException q?L*Luu+
{ wJvk
this("",0); G`;mSq6i
} F%{z EANm
U^-J_yq
wjOqCF"
public FileAccessI(String sName,long nPos) throws IOException ;[Esop
{ qzo)\,
oSavedFile = new RandomAccessFile(sName,"rw"); ?q5HAIZ`
this.nPos = nPos; JKCV>k
oSavedFile.seek(nPos); HDu|KW$o1
} mcQ\"9;pY
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(ueH@A"9;
public synchronized int write(byte[] b,int nStart,int nLen) }JT&lyO< b
{ *t={9h
int n = -1; >Wpdq(o
try{ R9+f^o`W
oSavedFile.write(b,nStart,nLen); Ag1nxV1M$
n = nLen; W^3'9nYU
} W$Aypy
catch(IOException e) qrt2uE{K
{ bs?4|#[K
e.printStackTrace (); *S Z]xrs
} C{ Z*5)
(hv}K*c{
R/^;,.
return n; o9v9 bL+X
} ~i}/
=)]RD%Oq
91#n Aj%
} #e9XU:9@g
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BTE&7/i21
/* a<V Mh79*
**SiteInfoBean.java HI)U6.'
*/ i l%9j
package NetFox; _b=})**
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/J,&G: Er
public class SiteInfoBean { z]O>`50Q
2Ju,P_<dt
CR|>?9V
private String sSiteURL; //Site's URL `R$bx 64
private String sFilePath; //Saved File's Path {Z[kvXf"mZ
private String sFileName; //Saved File's Name ):Ekf2
private int nSplitter; //Count of Splited Downloading File s: MJ{r(s
$5>x)jr:w+
,z0E2
public SiteInfoBean() +6Vu]96=KC
{//nSplitter的缺省值为5 F0Z cV>j}
//default value of nSplitter is 5 mOYXd,xd
this("","","",5); 9x9E+DG#(
} +Pn`AV1
k_%maJkXp
6AmFl<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) HMR!XF&JjC
{ 8ZO~=e
sSiteURL= sURL; Gv\fF;,R
sFilePath = sPath; nON"+c*
sFileName = sName; v/wR)9
this.nSplitter = nSpiltter; 061f
Ob-k`@_|
)v.\4Q4
} ]JI A\|b6
0j{KZy
a3(f\MMxE
public String getSSiteURL() y? 65*lUl
{ /p@0Q[E
return sSiteURL; zPb"6%1B
} #kQLHi3##
c-a;nAR
:#W>lq@H
public void setSSiteURL(String value) w;^7FuBaC
{ Aj=c,]2
sSiteURL = value; R~BW=Dz,e
} W{;LI WsZ
d _koF-7
fP1fm
public String getSFilePath() mDU-;3OqF
{ qk(u5Z
return sFilePath; *(<3 oIRS
} 9}Zi_xK&|e
E}=F
~3m} EL
public void setSFilePath(String value) 'MIM_m)H
{ <4Cy U j
sFilePath = value; {pB9T3ry]
} v#+tu,)V;
2VS#=i(B^
/ec~^S8X
public String getSFileName() N&lKo}hk
{ \[x4
return sFileName; 9L9mi<,
} <i1P~
q0 8
[x|{VJ(h
public void setSFileName(String value) &,`P%a&k
{ Aaix? |XN
sFileName = value; GpM_Qp
} J)Td'iT(
)F35WP~
BLhuYuON
public int getNSplitter() KHXnB
{ pG:)u cj
return nSplitter; u@zBE? g
} -^7n+ QX
uc;QSVWGy8
9Uh nr]J.
public void setNSplitter(int nCount) Y~M H
{ ]7{-HuQ8>}
nSplitter = nCount; n7Ia8?8-l
} RpY#_\^hI
} _u`W$EG L
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/* 7gQ~"Q
**Utility.java I^6zUVH
*/ Q}jl1dIq
package NetFox; ?2b9N~
[VP~~*b
3^zOG2
public class Utility { %@FTg$
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D}Lx9cL
public Utility() RA+k/2]y!
{ "$BWP
z<mU$<
[(N<E/m%B
} %fz!'C_4
P1ab2D
//线程睡眠 ]Z\.Vx
public static void sleep(int nSecond) R#Bdfmldq
{ ;=6~,k)
try{ 3J}bI{3
Thread.sleep(nSecond); up7]Yy;o=
} L1k_AC1.M
catch(Exception e) <[7.+{qfW
{ f"5vpU^5*
e.printStackTrace (); [nlW}1)46
} QY<2i-A
} X^H)2G>e
Dl%NVi+n
//日志 Pw'3ya8
public static void log(String sMsg) m.p{+_@M&
{ 8+1tys
System.err.println(sMsg); 7>J8\=
} #\$R^u]!
5!G}*u.
I%whM~M1+
public static void log(int sMsg) 3say&|kJ
{ JQ8wL _C>
System.err.println(sMsg); X}xy v
} d1#;>MiU
} ~8Z0{^
:_Y@,CpIEg
GKwm %A
/* PDo%ob\Ym
**TestMethod.java eVDI7W:(Sn
*/ *eytr#0B-
package NetFox; [x5T7=
>LwZ"IEV
T)]5k3{
public class TestMethod { Pz1pEyuL
2, ` =i
[L,Tf_t^Y
public TestMethod() ,r{\aW@
{ ///xx/weblogic60b2_win.exe /AP@Bhm
try{ F"3PP ~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); oToUpkAI
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); R1FBH:Iu
SiteFileFetch fileFetch = new SiteFileFetch(bean); _{6QvD3kg.
fileFetch.start(); X/TuiKe
} [(Pm\o
catch(Exception e){e.printStackTrace ();} @twClk.s
(yCFpb
#|34(ML
} ;z>)&F
hX]vZR&R
`bffw:;%
public static void main(String[] args) =LS?:Mhm
{ jyf[O -
new TestMethod(); Qd 1Q~PBla
} ]dc^@}1bN
} A\_cGM2
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