社区应用 最新帖子 精华区 社区服务 会员列表 统计排行 社区论坛任务 迷你宠物
  • 9951阅读
  • 0回复

http断点续传简单实现(java)

发帖
8
铜板
1641
人品值
95
贡献值
0
交易币
0
好评度
8
信誉值
0
金币
0
所在楼道
/* y/ ef>ZZ  
**SiteFileFetch.java U|Ta4W`k\  
*/ [:SWi1cK2  
package NetFox; <lE <f+  
import java.io.*; ]|P iF+  
import java.net.*; _^%,x  
(M.&^w;`,  
N64dO[op  
public class SiteFileFetch extends Thread { Cd}<a?m,  
VQ9/Gxdeo  
) ahA[  
SiteInfoBean siteInfoBean = null; //文件信息Bean Fyatd  
long[] nStartPos; //开始位置 sN01rtB(UT  
long[] nEndPos; //结束位置 6zuTQ^pz  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ou{2@"  
long nFileLength; //文件长度 % ^1V4  
boolean bFirst = true; //是否第一次取文件 D7Q$R:6|  
boolean bStop = false; //停止标志 [j/9neaye  
File tmpFile; //文件下载的临时信息 ]K,Tnyp  
DataOutputStream output; //输出到文件的输出流 K F!Yf\  
Od,qbU4O  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) fSvM(3Y<Qh  
public SiteFileFetch(SiteInfoBean bean) throws IOException _5Ct]vy  
{ >V8-i`  
siteInfoBean = bean; )cMh0SGcM1  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); jLHkOk5{:  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Wf>R&o6tr  
if(tmpFile.exists ()) 7} 5JDG  
{ 68C%B9.b'  
bFirst = false; |"CZT#  
read_nPos(); ud@%5d  
} <&g,Nc'5C  
else PmEsN&YP]  
{ 3kp+<$  
nStartPos = new long[bean.getNSplitter()]; 6) [H?Q  
nEndPos = new long[bean.getNSplitter()]; mLLDE;7|}  
} V#gK$uv  
C 7ScS"~  
84zSK)=Y  
uo%)1NS!  
} rlSeu5X6  
a fW@T2  
YHygo#4=8  
public void run() Pw`8Wj  
{ nV/G8SeI  
//获得文件长度 y'nK>)WG4  
//分割文件 j[J-f@F \Y  
//实例FileSplitterFetch E,x+JeKV  
//启动FileSplitterFetch线程 wc^tgE  
//等待子线程返回 h(u8&MHx  
try{ ">,|V-H  
if(bFirst) ag;pN*z  
{ czgO ;3-C  
nFileLength = getFileSize(); " 9wvPC ^  
if(nFileLength == -1) yEoF4bt  
{ 9x9T<cx  
System.err.println("File Length is not known!"); u(F_oZ~  
} 9ZsVy  
else if(nFileLength == -2) w4{<n /"  
{ U,{eHe ?>T  
System.err.println("File is not access!"); :vQrOn18p  
} U@)eTHv}6  
else i^Y+?Sx  
{ $AjHbU.I{  
for(int i=0;i<nStartPos.length;i++) Ed df2;-.  
{ ?(F6#"/E  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ,pQZ@I\z  
} ;) z:fToh  
for(int i=0;i<nEndPos.length-1;i++) bSi%2Onj  
{ VSI9U3t3w  
nEndPos = nStartPos[i+1]; Q%f^)HZGR  
} g63(E,;;J  
nEndPos[nEndPos.length-1] = nFileLength; J7Hl\Q[D1  
} bP$dU,@p~  
} e>7>j@(K]  
jB Z&Ad@e  
Q}K"24`=  
//启动子线程 s %``H`  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; M@H;pJ+B  
for(int i=0;i<nStartPos.length;i++) 4ber!rJM  
{ 'ud{m[|  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x$.^"l-vX  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5o'FS{6U  
nStartPos,nEndPos,i); U!?_W=?  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dI@(<R  
fileSplitterFetch.start(); 6"5A%{ J  
} 6"O+w=5B  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qHplJ "  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 2M#Q.F  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Ls$D$/:q?  
nEndPos = " + nFileLength); N06OvU2>xU  
// fileSplitterFetch[nPos.length-1].start(); "R1NG?; q  
#64-~NVL_  
(pCrmyB  
//等待子线程结束 FQ7T'G![  
//int count = 0; < #}5IQ5`Z  
//是否结束while循环 ~IfJwBn-i  
boolean breakWhile = false; tGh~!|P  
Ms5ap<q#  
HI R~"It$  
while(!bStop) bz2ztH9 n  
{ i$:*Pb3mV  
write_nPos(); v6M6>&RR|  
Utility.sleep(500); Vl /+;6_  
breakWhile = true; d *|Y o  
L~rBAIdD  
vrhT<+q  
for(int i=0;i<nStartPos.length;i++) JPc+rfF  
{ 8:c-k|CX  
if(!fileSplitterFetch.bDownOver) ]}-7_n#cC  
{ rq/yD,I,  
breakWhile = false; r6MMCJ|G  
break; 3G)#5 Lf<  
} kHghPn?8]  
} 2G67NC?+  
if(breakWhile) RXpw!  
break; rb2S7k0{  
Jr ,;>   
'EEJU/"u  
//count++; ug!s7fo^  
//if(count>4) J6s`'gFns  
// siteStop(); qo90t{|c  
} Ustv{:7v  
<ro7vPKNa  
uk< 4+x,2)  
System.err.println("文件下载结束!"); 8 S:w7Hr  
} &Fzb6/  
catch(Exception e){e.printStackTrace ();} B:;pvW]  
} 8>2.UrC  
j9x<Y]  
fcRxp{*zO  
//获得文件长度 _"Dv uR  
public long getFileSize() 7a =gH2]&  
{ L%*!`TN  
int nFileLength = -1; hYT0l$Ng  
try{ szZr4y<8|1  
URL url = new URL(siteInfoBean.getSSiteURL()); e#L8X {f  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); SIF/-{i(X  
httpConnection.setRequestProperty("User-Agent","NetFox"); [fya)}  
@Q ]=\N:  
7 S#J>*  
int responseCode=httpConnection.getResponseCode(); UqFO|r"M  
if(responseCode>=400) E:sf{B'&  
{ BOb">6C  
processErrorCode(responseCode); JgKO|VO  
return -2; //-2 represent access is error xjuN-  
} ?*G|XnM&  
c?f4Q,%|  
f}#~-.NGs  
String sHeader; c@!_ /0  
$Uq|w[LA  
-[4T  
for(int i=1;;i++) (^8Y|:Tz  
{ ~drS} V  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); zH?!  
//Utility.log(in.readLine()); jH5 k  
sHeader=httpConnection.getHeaderFieldKey(i); l[mWf  
if(sHeader!=null)  4C6YO  
{ 6"L cJ%o  
if(sHeader.equals("Content-Length")) U2tV4_ e  
{ &Cq`Y !y  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 75cW_t,g  
break; {NmWQyEv  
} T6y\|  
} 'Vzp2  
else EA@ .,7F  
break; i^X]j  
} xBThq?N?  
} zsEc(  
catch(IOException e){e.printStackTrace ();} BM%e0n7  
catch(Exception e){e.printStackTrace ();} APn|\  
m)ky*"(  
:[p}  
Utility.log(nFileLength); 59LZv-l  
)al]*[lY  
-]N x,{  
return nFileLength; 9tU]`f  
} .KB^3pOpx  
2@n{yYwy  
X[-xowE-  
//保存下载信息(文件指针位置) `&r+F/Ap2  
private void write_nPos() s [RAHU  
{ dc+>m,3$  
try{ |IeTqEu9  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 7Kr*P<-G  
output.writeInt(nStartPos.length); {g'(~ qv  
for(int i=0;i<nStartPos.length;i++) <prk8jSWV  
{ OZb-:!m*  
// output.writeLong(nPos); FZ{h?#2?  
output.writeLong(fileSplitterFetch.nStartPos); [SjqOTon{  
output.writeLong(fileSplitterFetch.nEndPos); j nkR}wAA  
} (+w*[qHe  
output.close(); h"[AOfTE$  
} MD}w Y><C  
catch(IOException e){e.printStackTrace ();} f&N gS+<K$  
catch(Exception e){e.printStackTrace ();} px A?  
} A9KET$i@v  
.Yamc#A-  
>2y':fO  
//读取保存的下载信息(文件指针位置) %8RrRW  
private void read_nPos() A]_7}<<N  
{ NlA,'`,  
try{ 2jA{SY-  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5c@,bIl *  
int nCount = input.readInt(); >2Y=*K,:  
nStartPos = new long[nCount]; ]{;gw<T  
nEndPos = new long[nCount]; $g^@AdE%  
for(int i=0;i<nStartPos.length;i++) KaLzg5is  
{ Z\(q@3C  
nStartPos = input.readLong(); -vAC"8)S  
nEndPos = input.readLong(); AmUr.ofu  
} SpIv#?  
input.close(); [$ubNk;!z  
} z{%<<pZ  
catch(IOException e){e.printStackTrace ();} @f_Lp%K  
catch(Exception e){e.printStackTrace ();} W- $Z(Z XL  
} ")1:F>  
*l(7D(#  
WJ]T\DI  
private void processErrorCode(int nErrorCode) *[Imn\hu  
{ `Y0%c Xi3  
System.err.println("Error Code : " + nErrorCode); m;$ b'pT  
} ,5P0S0*{  
[CTnXb  
'9%\;  
//停止文件下载 k`cfG\;r  
public void siteStop() ^L,K& Jd  
{ =bAx,,D#  
bStop = true; ]"pVj6O  
for(int i=0;i<nStartPos.length;i++) +X\FBvP&  
fileSplitterFetch.splitterStop(); dUD[e,?  
vJLK,[  
s2a{>II6  
} {Ea b j  
} x f'V{9*  
//负责部分文件的抓取 5p,RI&nlN  
**FileSplitterFetch.java W Tcw4  
*/ ;_XFo&@  
package NetFox; K,tQ!kk  
;gD})@  
%6t:(z  
import java.io.*; ./XYd"p  
import java.net.*; Ml`:UrU  
xW+6qtG`  
!@5 9)  
public class FileSplitterFetch extends Thread { `](e:be}  
qfX6TV5J}!  
44J]I\+  
String sURL; //File URL Mg+2. 8%  
long nStartPos; //File Snippet Start Position A_rG t?i  
long nEndPos; //File Snippet End Position i[i4h"$0  
int nThreadID; //Thread's ID 0RzEY!9g+  
boolean bDownOver = false; //Downing is over M^A48u{,"  
boolean bStop = false; //Stop identical I !- U'{  
FileAccessI fileAccessI = null; //File Access interface  C;v.S5x  
{% 6}'  
9FF0%*tGo  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s$IDLs,WM  
{ AI2~Jp  
this.sURL = sURL; [=C6U_vU  
this.nStartPos = nStart; v<k?Vu  
this.nEndPos = nEnd; ;cNv\t  
nThreadID = id; 2bz2KB5>  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 //B&k`u  
} -$\y_?}  
&.3"Uo\#  
&*o=I|pQ  
public void run() }ZYd4h|g\z  
{ 3s*mbk[J  
while(nStartPos < nEndPos && !bStop) XMZ,Y7  
{ {.`vs;U  
@?ebuj5{e  
P|`8}|}a  
try{ pR<`H'  
URL url = new URL(sURL); SV4E0c>  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p;a,#IJu  
httpConnection.setRequestProperty("User-Agent","NetFox"); v{RZJ^1  
String sProperty = "bytes="+nStartPos+"-"; #{0HYg?(f  
httpConnection.setRequestProperty("RANGE",sProperty); W@>% {eE  
Utility.log(sProperty); &{5,:%PXw  
UJUEYG  
KV91)U  
InputStream input = httpConnection.getInputStream(); \eTwXe]Pv  
//logResponseHead(httpConnection); G+9,,`2  
0mp/Le5  
qyb?49I  
byte[] b = new byte[1024]; t[HE6ea  
int nRead; VD AaYDi  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "37lx;CH  
{ v4<nI;Ux  
nStartPos += fileAccessI.write(b,0,nRead); /*~EO{o  
//if(nThreadID == 1) $B+8Of  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q)#B0NA;T  
} SZ7:u895E  
?9vuuIE  
m<G,[Yc  
Utility.log("Thread " + nThreadID + " is over!"); Lpkyoh v  
bDownOver = true; t mn tp  
//nPos = fileAccessI.write (b,0,nRead); wKh4|Ka  
} j{ ]I]\=?  
catch(Exception e){e.printStackTrace ();} alJ)^OSIe  
} 2F;y;l%  
} E#34Wh2z  
_ >?\DgjH  
k:i4=5^*GX  
//打印回应的头信息 z9f-.72"X  
public void logResponseHead(HttpURLConnection con) /A\8 mL8  
{ 'd0~!w  
for(int i=1;;i++) 810|Tj*U%  
{ c?Y*Y   
String header=con.getHeaderFieldKey(i); AD> e?u  
if(header!=null) :]K4KFM  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Z9E\,Ly  
Utility.log(header+" : "+con.getHeaderField(header)); `%bypHeSp  
else !vi> U|rh  
break; D_2:k'4  
} Q>qUk@  
} ux-/>enc  
umBICC]CU  
W ~<^L\Lu  
public void splitterStop() y8y5*e~A-)  
{ 1dY}\Sp  
bStop = true; Cl.x'v  
} !<|4C6X:4  
sfH_5 #w  
Sz $~P9  
} Oamg]ST  
]OhiYU4  
$QF{iV@6d4  
/* f^ZRT@`O  
**FileAccess.java Rr$-tYy6  
*//文件访问(定位,写) Oxnp0 s  
package NetFox; 2ACCh4(/P  
import java.io.*; Eh`7X=Z7E  
Ufj`euY  
KM0ru  
public class FileAccessI implements Serializable{ T.F!+  
QhFV xCA  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "9uKtQS0o  
RandomAccessFile oSavedFile; .<?GS{6 N  
long nPos; yF:1( 4  
0 JS?;fk  
bRDYGuC  
public FileAccessI() throws IOException e ,'_xV  
{ E`JI>7  
this("",0); 234p9A@  
} o 11jca|  
Xq4O@V  
E =67e=h  
public FileAccessI(String sName,long nPos) throws IOException R-wp9^  
{ ^6x%*/l|  
oSavedFile = new RandomAccessFile(sName,"rw"); Hvauyx5T  
this.nPos = nPos; ^0 )g/`H^>  
oSavedFile.seek(nPos); G't$Qx,IC  
} GKqm&/M*=  
;O5zUl-`  
Ty\R=y}}  
public synchronized int write(byte[] b,int nStart,int nLen) ;C#F>SG\S  
{ HWAdhDZ  
int n = -1; %Xg4b6<9  
try{ P:S.~Jq  
oSavedFile.write(b,nStart,nLen); \w>y`\6mX  
n = nLen; hFUlNJ  
} Q}JOU  
catch(IOException e) 2W(s(-hD  
{ m 0C@G5  
e.printStackTrace (); X0 5/uX{  
} h&iC;yj=  
P5V}#;v  
6wRd<]C  
return n; 8nqG<!,q  
} s[*rzoA  
.sW|Id )  
ODN /G%l  
} Paq4  
2qNt,;DQ  
@;4zrzQi7  
/* MY)O^I X$  
**SiteInfoBean.java +E+p"7  
*/ rKc9b<Ir  
package NetFox; s^TZXCyF o  
n6>#/eUH  
]cvwIc">  
public class SiteInfoBean { 0auYG><=  
FUzzB94a  
K3m/(jdO  
private String sSiteURL; //Site's URL -ad{tJV|  
private String sFilePath; //Saved File's Path :kV#y  
private String sFileName; //Saved File's Name }#+^{P3;  
private int nSplitter; //Count of Splited Downloading File }&D WaO]J7  
{WS;dX4  
klYX7?  
public SiteInfoBean() rXq.DvQ  
{//nSplitter的缺省值为5 c#]4awHU  
//default value of nSplitter is 5 3`?7 <YJ  
this("","","",5); T<>,lQs(a  
} .43'HV  
Y-z(zS^1  
\l0[rcEf  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =%O6:YM   
{ fbvL7* (  
sSiteURL= sURL; /s?`&1v|r  
sFilePath = sPath; A\DCW  
sFileName = sName; S@tLCqV4  
this.nSplitter = nSpiltter; ^ +\dz  
#%2rP'He  
5;WH:XM  
} ;;t yoh~t  
(,2S XV  
h" W,WxL8  
public String getSSiteURL() A{zN | S[  
{ (mB&m@-N  
return sSiteURL; 2pCaX\t  
} %2{ye  
Q{>k1$fkV  
T763:v  
public void setSSiteURL(String value) ?j.,Nw4FC  
{ C): 1?@  
sSiteURL = value; Nx;~@  
} ~8+ Zs  
1GRCV8 "Z^  
>R_&Ouh:  
public String getSFilePath() >'$Mp<  
{ Y@iS_lR  
return sFilePath; N~gzDQ3  
} ej d(R+  
/nsX]V6i  
pki%vRY  
public void setSFilePath(String value) r5/0u(\LB  
{ FV!q!D  
sFilePath = value; T::85  
} \@zHON(  
gJ{)-\  
Fo_sgv8O<  
public String getSFileName() ~?}Emn;t  
{ !< ";cw(q  
return sFileName; J;e2&gB  
} C) s5D  
0+ '&`Q!u  
5tk AFb4P  
public void setSFileName(String value) =qIp2c}Rx  
{ B$K=\6o  
sFileName = value; Q&;9 x?e  
} ?V=ZIGj  
r u%y  
EZGIf/ 3  
public int getNSplitter() eByz-,{P  
{ e *C(q~PQ  
return nSplitter; _H%c;z+  
} B3I`40#  
HC8e>kP9b  
'<<t]kK[N  
public void setNSplitter(int nCount) L*+@>3mu)  
{ ITBE|b  
nSplitter = nCount;  (ZizuHC  
} F>l] 9!P|m  
} ?l )[7LR4  
Avc%2 +  
\\qZl)P_  
/* ^x,YW]AS}  
**Utility.java O/C rd/  
*/ t:Q*gW Rh  
package NetFox; Lq^)R  
{\5  
=T@1@w  
public class Utility { q9_OGd|P  
* u>\57W  
o.!Dq7 R  
public Utility() M }D}K\)  
{ 2ilQXy  
vE?G7%,  
HV|,}Wks6s  
} r19 pZAc  
Otuf] B^s  
//线程睡眠 S\=Nn7"  
public static void sleep(int nSecond) )t#W{Gzfmh  
{ TJRCH>E[a  
try{ ^h6tr8yn  
Thread.sleep(nSecond); R 9\*#c  
} Yq KCeg  
catch(Exception e) %u'u kcL7  
{ 6&x@.1('z  
e.printStackTrace (); 7:1Lol-V  
} c@7rqHU-0  
} p5iuYHKk?  
ez$(c  
//日志 R m( "=(  
public static void log(String sMsg) }7Q%6&IR  
{ ga+dt  
System.err.println(sMsg); y)@wjH{6  
} K0>zxqY  
y N-9[P8C  
0(HU}I  
public static void log(int sMsg) f:} x7_Q  
{ sgFEK[w.y  
System.err.println(sMsg); k,*XG$2h  
} mzgfFNm^G)  
} Zy/_ E@C}u  
hgq;`_;1,  
0=YI@@n)  
/* qE"OB  
**TestMethod.java zDG b7S{  
*/ z03K=aZ  
package NetFox; 9'B `]/L  
WyiQoN'q  
|6- nbj  
public class TestMethod { 9* M,R,y  
@yYkti;4-  
zb3t IRH  
public TestMethod() =s6 opL)  
{ ///xx/weblogic60b2_win.exe 59u }W 0  
try{ 2?Vd5xkt  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 'g\4O3&_  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); H5|;{q:j  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Pm7}"D'/  
fileFetch.start(); tw@X> G1z  
} @0''k  
catch(Exception e){e.printStackTrace ();} jP.dDYc  
8s@3hXD&  
>t+P(*u  
} (bS&D/N.  
h?U O&(  
"{t$nVJ  
public static void main(String[] args) P%n>Tg80M  
{ a<e[e>  
new TestMethod(); (ZlU^Gw#UB  
} z1a7*)8P  
} u ga_T  
点击下载更多相关资料
评价一下你浏览此帖子的感受

精彩

感动

搞笑

开心

愤怒

无聊

灌水
描述
快速回复

您目前还是游客,请 登录注册
温馨提示:欢迎交流讨论,请勿纯表情、纯引用!
认证码:
验证问题:
10+5=?,请输入中文答案:十五